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How many uf do i need to cope with the HDD inrush current

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    #21
    Re: How many uf do i need to cope with the HDD inrush current

    "When i connected the caps it caused my main HDDs to spin down"
    you saying you connected caps to machine whilst running ?

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      #22
      Re: How many uf do i need to cope with the HDD inrush current

      @eccerr0r
      if i only knew what sensors were what on the board (main reason i have not started OCing my CPU)
      Code:
      evilkitty@Z97K1LLER:~$ sensors
      coretemp-isa-0000
      Adapter: ISA adapter
      Physical id 0: +38.0°C (high = +80.0°C, crit = +100.0°C)
      Core 0:     +35.0°C (high = +80.0°C, crit = +100.0°C)
      Core 1:     +35.0°C (high = +80.0°C, crit = +100.0°C)
      Core 2:     +37.0°C (high = +80.0°C, crit = +100.0°C)
      Core 3:     +38.0°C (high = +80.0°C, crit = +100.0°C)
      
      nct6791-isa-0290
      Adapter: ISA adapter
      in0:          +0.90 V (min = +0.00 V, max = +1.74 V)
      in1:          +1.71 V (min = +0.00 V, max = +0.00 V) ALARM
      in2:          +3.41 V (min = +0.00 V, max = +0.00 V) ALARM
      in3:          +3.39 V (min = +0.00 V, max = +0.00 V) ALARM
      in4:          +1.03 V (min = +0.00 V, max = +0.00 V) ALARM
      in5:          +1.02 V (min = +0.00 V, max = +0.00 V) ALARM
      in6:          +0.00 V (min = +0.00 V, max = +0.00 V) ALARM
      in7:          +3.52 V (min = +0.00 V, max = +0.00 V) ALARM
      in8:          +3.34 V (min = +0.00 V, max = +0.00 V) ALARM
      in9:          +1.02 V (min = +0.00 V, max = +0.00 V) ALARM
      in10:          +0.00 V (min = +0.00 V, max = +0.00 V)
      in11:          +1.01 V (min = +0.00 V, max = +0.00 V) ALARM
      in12:          +1.22 V (min = +0.00 V, max = +0.00 V) ALARM
      in13:          +0.86 V (min = +0.00 V, max = +0.00 V) ALARM
      in14:          +0.21 V (min = +0.00 V, max = +0.00 V) ALARM
      Chassis Fan 1 Speed:   0 RPM (min =  0 RPM)
      CPU Fan 1 Speed:    383 RPM (min =  0 RPM)
      Chassis Fan 3 Speed:  404 RPM (min =  0 RPM)
      Chassis Fan 4 Speed:  440 RPM (min =  0 RPM)
      Power Fan Speed:     0 RPM (min =  0 RPM)
      CPU Fan 2 Speed:    444 RPM
      SYSTIN:         +32.0°C (high = +0.0°C, hyst = +0.0°C) ALARM sensor = thermistor
      CPUTIN:         +75.0°C (high = +80.0°C, hyst = +75.0°C) sensor = thermistor
      AUXTIN0:        +127.0°C  sensor = thermistor
      AUXTIN1:        -128.0°C  sensor = thermistor
      AUXTIN2:        +25.0°C  sensor = thermistor
      AUXTIN3:        +103.0°C  sensor = thermistor
      PECI Agent 0:      +37.5°C (high = +80.0°C, hyst = +75.0°C)
                       (crit = +100.0°C)
      PCH_CHIP_CPU_MAX_TEMP:  +0.0°C 
      PCH_CHIP_TEMP:      +0.0°C 
      PCH_CPU_TEMP:      +0.0°C 
      intrusion0:      ALARM
      intrusion1:      ALARM
      beep_enable:      disabled
      the system is at a idle load, so it is well within the limits of the PSU to run it
      i know i can handle a 120W CPU full load, and i am only using a 88W cpu at idle
      i should be fine with a 450-500w PSU
      but maybe this PSU is getting weak with its age (5 years and 7 months)
      maybe i should upgrade to a seasonic focus 550w

      @petehall347
      Yes, i just plugged the new wire with caps into the modular jack (empty hot swap bays)
      the caps had no charge and they are low esr so i guess they sucked up some power quickly
      was that a bad thing to do?
      well as close as you can get to idle running a GUI (server idle != client idle)

      I realize my PSU model has had some reversions over the years
      Mine has a ball bearing fan, is semi-modular, and has 5pin single row pings for sata/molex cables; it has 5 plugs for them and a 6pin for the GPU
      label says it has two 12v rails each rated at 20A
      EDIT: https://content.hwigroup.net/images/...ronze-520w.jpg
      edit: https://jmtcomputer.com/image/cache/.../5-500x500.jpg
      Last edited by evilkitty; 03-31-2018, 06:53 PM.

      Comment


        #23
        Re: How many uf do i need to cope with the HDD inrush current

        Oh I forgot that the sample rate of the onboard sensors are insufficient, you'll need an external datalogger to see the droop.

        Comment


          #24
          Re: How many uf do i need to cope with the HDD inrush current

          momentary short circuit with cap . just for fun leave it connected and reboot . maybe check volt drops across connections . or start with supply sag .

          Comment


            #25
            Re: How many uf do i need to cope with the HDD inrush current

            i doubt a multimeter has a high enough refresh rate to see the drop
            but the new caps are right at the end of the cable 3mm of wire then enough space to solder them, maybe 7mm, the next drive is 40mm from there
            Originally posted by petehall347 View Post
            momentary short circuit with cap . just for fun leave it connected and reboot . maybe check volt drops across connections . or start with supply sag .
            did not trip the short circuit protection; thought i know i have had a short before, just figured never shut off cause the wire could not handle it and brut to a crisp (this circuit was on a switch)
            though in the past i had a bad wire (26 or 28 awg) that shorted i think the insulation failed when i applied heat shrink to the sleeving, the wire stopped working after a little while and it did not trip it but the wire brut up
            i guess i have abused this unit a couple times; probably should check a few caps in the PSU, now that the warranty is out
            Last edited by evilkitty; 03-31-2018, 06:38 PM.

            Comment


              #26
              Re: How many uf do i need to cope with the HDD inrush current

              Can you duplicate the issue without the hotswap bay (BTW, the SATA PSU connector but not molex4 is stagger pinned and was designed for hot swapping, likewise the data cable.) Just want to make sure it's the power cable and perhaps not the hot swapped data cable confusing the SATA controller.

              Comment


                #27
                Re: How many uf do i need to cope with the HDD inrush current

                Originally posted by evilkitty View Post
                Yes, i just plugged the new wire with caps into the modular jack (empty hot swap bays)
                the caps had no charge and they are low esr so i guess they sucked up some power quickly
                was that a bad thing to do?
                well as close as you can get to idle running a GUI (server idle != client idle)
                Would you hitch a trailer to your car while your car was in motion? Imagine the trailer sitting on the side of the road with a few hundred feet of heavy cable attaching it to your vehicle. So, your vehicle gets up to a nice, comfortable driving speed... then the slack in the cable runs out and the vehicle suddenly has an extra "load" to deal with.

                How would your car react to this sudden addition of extra weight? Would the engine keep the car running at the same steady speed? Or, would you experience a sudden jolt as the engine groaned from the unexpected new load?

                [Of course, as the trailer picked up speed, the engine would see less of the "dead" load and, eventually, just the marginal increase caused by the additional rolling friction losses of the trailer.]

                An uncharged cap appears as a dead short, momentarily. Much like the trailer appears to your car's engine (until it has had a time to come up to speed).

                The caps and the hotswap drive resemble that trailer. If they are present "from the beginning", then the power supply comes up with them as part of the load and, as long as the capacity of the power supply isn't exceeded, all is well -- everything comes up "together". OTOH, slap them onto the power supply while it is running and there is a sudden "jolt" which manifests as a (temporary) drop in output voltage.

                How quickly the power supply recovers depends on the design and topology of the power supply. A power supply with excellent "load regulation" can tolerate large changes in the "size" of the load with minimal impact on the output voltage; the supply "adapts" to the load, well.

                [One way to ruin load regulation is by adding series resistance between the power supply and load; the load sees it as a "shittier power supply"]

                To ease the requirements on the power supply, you want to minimize how much of a "jolt" it has to accommodate. That's why systems with large disk arrays stagger the spin-up of the drives (typically 6-12 seconds per spindle). This allows the power supply to take on smaller "jolts" instead of one GIANT one!

                E.g., my "disk shelfs" (12-15 drives) take a couple of minutes to come on-line.

                Comment


                  #28
                  Re: How many uf do i need to cope with the HDD inrush current

                  Originally posted by eccerr0r View Post
                  Oh I forgot that the sample rate of the onboard sensors are insufficient, you'll need an external datalogger to see the droop.
                  A "conventional" multimeter (e.g., Simpson) may be fast enough. Note that you can also connect it in a differential configuration with more volts/division so the droop is "amplified" in the meter's indicator.

                  You might also try an LED or incadescent lamp (differential) and hope to catch a momentary "blink" (or "wink", depending on how wired)

                  [Also, more esoteric measures to capture the glitch and "store" it for more leisurely viewing]

                  Comment


                    #29
                    Re: How many uf do i need to cope with the HDD inrush current

                    I was unable to see any flicker in my case LEDs, i have some SMD 3528 LED strips; but that is just the 12v not the 5v

                    Comment


                      #30
                      Re: How many uf do i need to cope with the HDD inrush current

                      Originally posted by evilkitty View Post
                      I was unable to see any flicker in my case LEDs, i have some SMD 3528 LED strips; but that is just the 12v not the 5v
                      You misunderstood. I was saying to hack together a "visual indicator" out of an LED or a wheat-germ incandescent specifically for the purpose of this test. Wire it between the "suspect" power signal and a known, stable one. E.g., another power supply, a "battery", or even a large cap -- sized not to droop while powering the indicator through the "droop" -- hiding behind a blocking diode to isolate it from any SUSPECTED droop in the suspected power signal (the cap plays the role of a "battery" in this case).

                      Normally, the "battery" voltage and the "suspected power" signal will be the same. Or, close enough that the indicator won't illuminate. When/if the power signal droops, the battery won't and a potential will develop across the lamp causing it to momentarily illuminate (maybe just a dim glow, depending on how large of a droop and how prolonged) for the duration of the droop. You would view it shielded from other light sources.

                      Using an LED gives you a faster response time (you can see very short "blinks"). But, requires a couple of volts of difference to forward bias the indicator. So, you would have to tweek your "battery" to be at a nomminal voltage that is higher than your "suspected power voltage" but not yet high enough to light the indicator.

                      I.e., you're kludging together something to monitor a difference between two signals. By contrast, your case LEDs are designed to work off of a larger signal (voltage) and may be less sensitive to the small changes that are disturbing the CPU/disk/whatever.

                      Walk into a brightly lit room. Dim the lights by 10% -- will you notice it?

                      Now, walk into a room that is lit so dimly that you can barely see anything. Dim those lights by 10% -- suddenly everything "goes black"...

                      Comment


                        #31
                        Re: How many uf do i need to cope with the HDD inrush current

                        Ok so i pick up one of my many green LEDs
                        place it along with a small resistor between PSU's +12v and a batteries +12v
                        and connect both grounds together
                        So IF the voltage of the PSU drops below the fV of the LED relative to the battery it will light

                        Comment


                          #32
                          Re: How many uf do i need to cope with the HDD inrush current

                          Originally posted by evilkitty View Post
                          Ok so i pick up one of my many green LEDs
                          place it along with a small resistor between PSU's +12v and a batteries +12v
                          and connect both grounds together
                          So IF the voltage of the PSU drops below the fV of the LED relative to the battery it will light
                          Yes, but that means the supply would need to sag by a few volts to get any response. You might have to hook the anode to a higher "battery" voltage to detect smaller changes.

                          Note that this is a really piss poor way of doing things. But, would give you SOME indication of the size of the "sag" (you can try lowering the battery voltage to get an idea of how "deep" the sag).

                          A better way to do it would be with a DSO set to trigger on a falling signal. But, if you don't happen to have one handy...

                          Or, a peak detecting meter with the negative lead tied to the reference and the positive lead tied to your power line (again, looking to measure the DIFFERENCE between them and "capture" it)

                          You can also try powering the "windows" disk off of a stable power supply so it is not impacted by any fluctuations in the HS power leads. (I'm not convinced that you actually are pursing the right "problem"!)

                          Tell us, again, why you need the hot swap ability?? And, why you can't get it by putting the drive(s) in external USB enclosures (with their own power supplies)?

                          Comment


                            #33
                            Re: How many uf do i need to cope with the HDD inrush current

                            I use them on occasion; i have a box of old hdds (40 to 160 and a 640GB) i use
                            i am using cheap tray-less bays
                            in my bios i do have these bays set as hot swap; it also lets me define of drives are HDDs or ssds (no idea why)
                            If i need to backup something of somebody old computer before reformatting it comes in handy; if they have very little i will just scp it over the network from a live usb
                            Last edited by evilkitty; 04-02-2018, 05:10 AM.

                            Comment


                              #34
                              Re: How many uf do i need to cope with the HDD inrush current

                              Originally posted by evilkitty View Post
                              I use them on occasion; i have a box of old hdds (40 to 160 and a 640GB) i use
                              i am using cheap tray-less bays
                              in my bios i do have these bays set as hot swap; it also lets me define of drives are HDDs or ssds (no idea why)
                              If i need to backup something of somebody old computer before reformatting it comes in handy; if they have very little i will just scp it over the network from a live usb
                              Your problem appears to be related to the drive "sharing too much" (hardware) with the hosting computer. Whether that is the source of power or the disk interface. Hence the attempts to "move" the drive to a configuration that shares less (different disk controller, isolated power supply, etc.)

                              Most of my machines support hotswapping. But, I don't use it on any of them -- apprehension that "something might go wrong" (and I can't afford to put hundreds of megabytes of data at risk over an OS/hardware "glitch" or "bug").

                              My first PC had a tiny 60MB (that's an M, not a G) drive (before they were even called "IDE" -- everyone else was still using ST506 drives/controllers). As 300MB drives were outrageously expensive, I adopted the technique of using offline storage and disciplining myself to only "need" certain programs and data during particular "system configurations".

                              I would push the contents of the system disk off onto 9T tape. Then, load the programs and data from a different reel for whatever I had to work on, next (e.g., if designing a circuit, I'd load the schematic editor, part libraries, PCB layout tools, etc. -- after pushing whatever tools were currently on the disk off onto a blank tape).

                              Of course, with a 60MB cap on the size of the medium, this didn't take much time (mainly, the time required to find the correct tape and load it).

                              Eventually, I added a SCSI HBA to my machines. This would allow me to access an external SCSI disk drive. Because it was external, I could disconnect it and/or attach additional (or "other") disks to the bus without crashing the running system.

                              In addition to removing the cap on the total amount of storage that I could have, it also let me move large chunks of data between machines at speeds that even the network (10Base2, at the time) couldn't support: unplug disc enclosure, walk across room, plug into other machine in a matter of seconds!

                              As external enclosures are large (compared to the bare drive, inside), I eventually moved to using "disk shelfs" configured as JBOD's. This would let me remove individual drives from a "collection" of many drives (12, 15 or 7, depending on the enclosure I was using). The additional storage that a drive represented no longer had to come with an attached "power supply and case"! And, I could move those "bare" drives to any machine that had a compatible disk shelf!

                              USB made all of this easier. The enclosures were smaller -- closer to the size of the drive contained within. And, the interface was more universal -- I didn't need to install a SCSI HBA in every computer to have access to ALL of the USB-mounted media! And, the interface was inherently hot-swappable (save for MS's piss-poor implementation).

                              But, even USB enclosures eat up a fair amount of space -- there is SOME added size for the enclosure plus its external wall wart (as they aren't always interchangeable unless you limit yourself to certain types of enclosures).

                              SATA allowed me to use bare drives in a USB "dock" (easier than having to wrestle a 40 pin ribbon cable off of a PATA drive). I could now store almost twice as many spindles as I could have, previously, in enclosures!

                              I've now pretty much standardized on Dell sleds that I can move between disk shelfs and an old Pe840 "server" (gives me 4 slots into which I can mount drive sleds). The Pe840 (and the sleds!) will support SAS and SATA drives. And, I can replace the 4 slot disk cage with a 4 slot SCSI disk cage if I need to do a lot of work on SCA drives. Unfortunately, FC-AL and "plain" SCSI I have to address one drive at a time...

                              I can connect a SATA drive to a "foreign" computer by mounting it in that USB dock (though I currently can't do this with SAS, SCA, FC-AL or SCSI drives). And, I have "adapters" that allow me to convert SATA drives to SAS if I need to mix and match them (while the Pe840 will support both types, it won't allow you to mix-and-match; so, copying a SAS drive onto a SATA -- or vice versa -- is handled with these.)

                              [The "boot disk" in the Pe840 is housed in a sledless hot-swap carrier. But, only so I can swap out the entire OS (replace with a different boot disk) to make those 4 disk slots available to that "other" OS]

                              But, I still have a bunch of media on USB drives (esp the larger "consumer" drives -- 1-4TB) though they are rarely spun up. These (along with the Pe840 mounted drives) I access over the network. E.g., I no longer keep CD/DVD media on hand. Instead, I create ISO's of all the media and store them on spinning rust. When I need access to one, I either copy the ISO to a machine and mount it (using various utilities). Or, burn real media from that image (e.g., when installing a new OS).

                              Likewise, if I need to move a virtual machine to another host, I can just pull the disk image across the network.

                              [I've been systematically cleaning off the smaller (<1TB) USB drives and recycling them (if small or IDE) in favor of SAS and SATA "sledded" drives. There are some USB enclosures that I will keep -- like the one that holds my Windows offline updates -- as it is a more convenient "portable" medium; I can drag it over to a friend's home if I need to install an OS/updates!]

                              The point of all of this is to highlight that I maintain a very strong separation (hardware/software/OS) between this "tertiary" storage and the storage that my machines use to perform their basic duties. There's less interaction between the machine and the medium as the media are changed. Less that is likely to "glitch". Less risk to spindles!

                              USB2 is admittedly slow (many machines can't move more than 20MB/s -- about 1GB/min -- over those interfaces). USB3 considerably faster (often a consequence of how/where the USB controller ties into the CPU). Would you be better served "moving" your "hotswap bay" into a USB enclosure? Or, into a free-standing NAS (and accessing the content over the wire)?

                              Will you ever be sure that you've sorted out your current problem? (and, how much time do you want to spend trying to solve it vs. doing "real work"?)

                              Comment


                                #35
                                Re: How many uf do i need to cope with the HDD inrush current

                                Originally posted by evilkitty View Post
                                I remade my cable using better quality wire (without adding caps to the wire)
                                this alone did not fix the issue
                                added a drive during a benchmark:



                                After adding 470uf caps on +5 and +12 (Low ESR Panasonic, rated at 25v)



                                it did not help,
                                When i connected the caps it caused my main HDDs to spin down

                                * The large drop in the read speed is when i connect a second HDD in my second bay
                                I don't see how this is a surprise. If we looked at this simply from a capacitors ability to quickly, supply power to the drive, putting a cap, right at the drives power connector is not going to improve the situation because they can only be charged as quickly as the caps behind them, in the PSU, can supply it to them. You need to reinforce the power supply with fresh, high quality caps if you're going to play with caps.

                                I like to replace the mains caps in PSU's, too. I used to use Panasonic TS-ED's when they were available. Refresh the secondaries of course.
                                Presonus Audiobox USB, Schiit Magni 3, Sony MDR-V700

                                Comment


                                  #36
                                  Re: How many uf do i need to cope with the HDD inrush current

                                  ^ You could add supercaps. 10F or so at each drive should hold them up fine....
                                  Things I've fixed: anything from semis to crappy Chinese $2 radios, and now an IoT Dildo....

                                  "Dude, this is Wyoming, i hopped on and sent 'er. No fucking around." -- Me

                                  Excuse me while i do something dangerous


                                  You must have a sad, sad boring life if you hate on people harmlessly enjoying life with an animal costume.

                                  Sometimes you need to break shit to fix it.... Thats why my lawnmower doesn't have a deadman switch or engine brake anymore

                                  Follow the white rabbit.

                                  Comment


                                    #37
                                    Re: How many uf do i need to cope with the HDD inrush current

                                    Originally posted by Logistics View Post
                                    I don't see how this is a surprise. If we looked at this simply from a capacitors ability to quickly, supply power to the drive, putting a cap, right at the drives power connector is not going to improve the situation because they can only be charged as quickly as the caps behind them, in the PSU, can supply it to them. You need to reinforce the power supply with fresh, high quality caps if you're going to play with caps.
                                    "Local" bulk decoupling prevents larger IR drops from occurring on the interconnect wiring because it "knocks down" that peak current demand.

                                    All you need to do is have enough "energy" available, locally, to carry the load through its period of peak demand. The power supply only has to supply the AVERAGE demand of the load.

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