PC Restarting/ Shutting off abruptly.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

I'm sure you are going to play away this graph I post below by saying something like "The software Anandtech uses is incorrect, SATA 6 is only faster the first few milliseconds because I said so"




Source; http://www.anandtech.com/show/3812/t...realssd-c300/3

I'm not talking about SDD drives I'm talking about disk drives.
[Personally I think SSD drives are a stupid choice because of their high cost and short useful lifetime, but that's a whole nuther argument.]

The interface speed doesn't control the sustained speed of a file transfer once the buffer is full.
- The head-disk transfer rate does. [aka Media Transfer rate.]
- Head-disk transfer rates are just getting up around 100 Mb/sec now.
- Last I looked some 10k RPM drives have almost achieved 120 Mb/s at the heads but 7200 RPM drives haven't hit 100 Mb/s yet.
[Notice how most companies dropped the Media Transfer rate spec out of their publicized spec sheets right about the time SATA came out.]
-
A 1.5 G/s drive with a 16 Mb buffer fills the buffer in 0.01 sec.
- After it's full the rest of the transfer is bottle-necked at the heads/disc speed.

.

[Per Hansson]

Re: PC Restarting/ Shutting off abruptly.

PCBONEZ; eh no, you said SATA, not mechanical harddive
But since you are gonna just say otherwise again let me quote you;

Guess what.
SATA 3.0 doesn't any faster than SATA 1.5.
[Except for maybe the first 4-5 milliseconds.]
Same thing.
The stuff you see in ads is bull shit.
You see it so many times you believe it.

Oh, and mechanical harddives have achieved 157MB/s transfer speed from their platters, source; http://www.tomshardware.com/reviews/...gb,2600-5.html
Also over 2 years ago there where drives that could manage well over 100MB/s from their platters, source; http://www.anandtech.com/show/2519

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

My post didn't mention drive type.
Unless SDD is specifically called out a reasonable person assumes a traditional drive.
[Not to mention on numerous occasions I've said I consider SSD a stupid choice.]

- I just clarified what I meant.
- Get over it.

157MB/s
OH GOOD.. - They are up to 10% if the 1.5G/s SATA interface speed...
And COOL! -- Those drives can do 5% of 3Gb/s SATA Speed.
-- What a huge benefit that interface speed is in the real world!

Thanks for reinforcing my point.

.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

SSD makes as much sense as buying a $100K car that disintegrates after 20k miles.

.

[Scenic]

Re: PC Restarting/ Shutting off abruptly.

157MB/s
OH GOOD.. - They are up to 10% if the 1.5G/s SATA interface speed...
And COOL! -- Those drives can do 5% of 3Gb/s SATA Speed.
-- What a huge benefit that interface speed is in the real world!

uhm.. the SATA interface is labeled in gigabit/s ... not gigabyte/s..
(unlike the PATA/IDE interface where ATA100 actually meant 100MByte/s)

1.5GBit/s SATA = 192MByte/s (theoretical)
3.0GBit/s SATA = 384MByte/s (theoretical)
6.0GBit/s SATA = 768MByte/s (theoretical)

real world MByte/s values are quite a lot lower due to overhead though..

same thing for USB 2.0. that's supposed to be 480MBit/s.. which translates into (theoretical) 60 MByte/s ... in the real world you won't get more than 30-35MByte/s out of it though.. overhead/protocol again..

why it was labeled in Gigabit/s instead of Megabyte/s or Gigabyte/s ...?
marketing bullshit.
they wanted to make SATA150 (1.5GBit) SOUND faster than the (at that time) most common & fastest PATA/IDE interface, ATA133 (with 133MByte/s)
in the real world though, protocol overhead and the harddisks in general (which didn't even use the full potential of ATA133 at that time) it was NOT faster...
some harddrives were actually slower when connected via SATA than the same disk in the PATA/IDE version..

[Per Hansson]

Re: PC Restarting/ Shutting off abruptly.

"My post didn't mention drive type."

Exactly, your post mentioned the protocol, SATA and nothing else, i.e. that SATA revision 2 is no more better than SATA revision 1

"SSD makes as much sense as buying a $100K car that disintegrates after 20k miles."

SSD's have a stated life that outlasts normal harddrives, sure it is only marketing talk but I sure have not heard about SSD's dropping like flies, and yet they have been on the market for years now (except for firmware bugs but that is normal in cutting edge tech and also covered by warranty just like premature failures)

"OH GOOD.. - They are up to 10% if the 1.5G/s SATA interface speed..."
"And COOL! -- Those drives can do 5% of 3Gb/s SATA Speed."

No, they can do 55% of the SATA 3Gb/s speed

Just to clarify I am uncertain if PCBONEZ means SATA revision 3.0 or SATA 3Gbps in his posts, so here are the actual speeds;

SATA 1.0 = 1.5Gb/s
SATA 2.0 = 3.0Gb/s
SATA 3.0 = 6.0Gb/s

Now since they use 8b/10b encoding for SATA the maximum transfer rate becomes these limits respectively for each revision (excluding protocol overhead etc);
143.05MB/s
286.10MB/s
572.20MB/s

Calculation is; (speed in bytes*8/10/1024/1024/8)

Now can we please get back to the off topic discussion of how PFC fools all meters sold in UK (and I presume you mean Europe aswell then) as it was not the UK that made it law that powersupplies over 75w must have a PFC circuit, but the EU, directive IEC 555-2

http://en.wikipedia.org/wiki/AC_powe...apparent_power
Engineers care about apparent power, because even though the current associated with reactive power does no work at the load, it heats the wires, wasting energy. Conductors, transformers and generators must be sized to carry the total current, not just the current that does useful work.

http://en.wikipedia.org/wiki/Power_f...power_supplies
This presents a particular problem for the power companies, because they cannot compensate for the harmonic current by adding simple capacitors or inductors, as they could for the reactive power drawn by a linear load. Many jurisdictions are beginning to legally require power factor correction for all power supplies above a certain power level.

http://en.wikipedia.org/wiki/Power_f...bution_systems
The significance of power factor lies in the fact that utility companies supply customers with volt-amperes, but bill them for watts. Power factors below 1.0 require a utility to generate more than the minimum volt-amperes necessary to supply the real power (watts). This increases generation and transmission costs. For example, if the load power factor were as low as 0.7, the apparent power would be 1.4 times the real power used by the load. Line current in the circuit would also be 1.4 times the current required at 1.0 power factor, so the losses in the circuit would be doubled (since they are proportional to the square of the current). Alternatively all components of the system such as generators, conductors, transformers, and switchgear would be increased in size (and cost) to carry the extra current.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

You haven't presented anything the changes my opinions.

You guys buy whatever salesmen tell you....
I'm happy to let you hold that as the gospel truth.

SSD makes as much sense as buying a $100K car that disintegrates after 20k miles.

On disk drives interface speed is advertising hype aimed at gullible people.
[Only works for bursts...]

Benefits of PFC are also bogus advertising hype aimed at gullible people.

I know we've been through all these arguments before anyway in other threads.
... and I have 4 pallets coming in today I have to test/inventory.

[bhvm]

Re: PC Restarting/ Shutting off abruptly.

Bones, I have to agree with your anger on the marketing lies.

SATA itself is a bogus standard in my view... 1st Gen SATA was not much faster (theoreticaly) than ATA 133.

And when they ARE making a new standard, why not make it good and useful in the first place? Where's the power over SATA feature they promised? USB has been doing that since years. I suppose USB 3.0 is going to be the gold standard for external AND internal HDDs.

THis marketing funda is not just in tech... but everywhere... Look at food...Cars...Tools.... Clothes... its all hyperbole.

[Per Hansson]

Re: PC Restarting/ Shutting off abruptly.

bhvm; I agree, SATA physical construction is very poor
Original spec does not call for locking tabs, and it is also easy to break the SATA contact on the HDD PCB (Not that I've done it but seen many who have)
However I don't agree that USB would be used as a replacement inside computers, it is simply a much less efficient protocol (It is host based unlike Firewire and SATA which can communicate without interrupting the host systems CPU)

PCBONEZ,
Why did you reiterate the same thing about SSD's as in your previous post?

I think most people on this forum know how a harddrive works, i.e. that it has a small cache buffer for keeping track of things and also for caching a small amount of data...
Of course most people on this forum would also know this buffer is used for small burst transfers

Lastly I am very surprised by your comment on PFC
I don't think anyone in this thread (excuse me if I missed it) have said that PFC increases the efficiency of the PSU, or infact is to any benefit to end consumers at all?

What has been said is that it increases the power factor of the electrical distribution system, allowing power companies to use smaller gauge wiring, smaller transformers and smaller generators
I said in my first post that this is a "green thinking" (not that I give a shit about green things)
Because it allows the power companies to reduce their losses
Next you stated that those losses are carried as heat into the consumers own PFC PSU, but that is not true, to give an example if the heat caused by not having PFC and having PFC was dumped in the customers own PSU in the later case we would have this problem;
1kW PSU, no PFC
1000w with PF 0.55 = 450 var (volt-ampere reactive)

The same PSU with PFC
1000w with PF 0.99 = 10 var (volt-ampere reactive)

Now if the PSU with PFC truly was moving the entire heat load from the power company of 450 var to the customers PSU don't you think it would be quite problematic to get rid of those 450 watts of heat? (In addition to the actual switching losses inside the PSU, being anywhere from 10>20%

And please, we need some proof of your statement that PFC fools all meters sold in UK (and I presume you mean Europe aswell then) as it was not the UK that made it law that powersupplies over 75w must have a PFC circuit, but the EU, directive IEC 555-2

[bhvm]

Re: PC Restarting/ Shutting off abruptly.

Most annoying thing about SATA is that one has to lug an extra ugly wall-wart to power external Drives, while USB 3.0 supplies 0.9A of current (maybe more) right at the port

[severach]

Re: PC Restarting/ Shutting off abruptly.

The increased current from the reactive power wastes heat for a few miles of copper until it hits the power factor correction capacitors on the power lines. Putting this correction into the the power supply reduces this waste current to a few feet of copper. The power company has to run larger wire to handle the extra current and our power bills will be increased to cover. PFC is a nice neighbor problem. There's no benefit if I do it but there's a benefit if everyone does it. Such problems often end up at the government's doorstep.

Enough talk! Now let's have numbers from test equipment.

After getting a Kill A Watt and having fun with watt, VA, and power factor measurements I added PPFC tranformer from a dead Dell Lite-On 250W power supply to a Dell Lite-On 350W power supply that didn't come with one. Because of this discussion I added a DPDT switch so I could switch the PPFC transformer off and on in a running system to see how the power factor and consumption changes.

GX280 Tower, Dell NPS-250KB, GeForce 8600 GTS, 3 HD, add in cards, Windows: 121W/167VA = 0.73 Power Factor
GX280 Dell PS-6371-1DF-LF PPFC on: 121W/163VA = 0.74 power factor
GX280 Dell PS-6371-1DF-LF PPFC off: 125W/186VA = 0.66 power factor

The watt numbers move around but after watching them a while it is clear that the PPFC reduces the consumption by 4 watts. The reason it uses less power with PPFC on is simple. Supplies with PPFC do not have a thermistor so I wired the switch to switch off the thermistor when the PPFC transformer is switched on. A thermistor is less efficient than a PPFC transformer.

PPFC is green all the way around.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

As I said in post 107 before the moose interjected I'm going to swamped for a while and I don't have time to argue in any detail.
Not my fault you guys showed up late to the party.

Feel the need to point out the error in reason in severach's little experiment and his conclusions though.

The claim appears to be that PFC makes the rest of the system more efficient.
- BOGUS!
The PF of DC is 1.0.

Further: If the load was indeed constant in both tests then the energy used by the PSU stages after PFC and by the rest of PC were identical in both tests.
The 'consumption' is identical.

In other words all the test PROVES is that PFC screws with watt meters resulting in bogus data.
.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

Since I won't be here much and PFC has been around a long while now, why don't you boys use the time and go find one single instance or a power company switching to smaller generators, transformers, and wire.

While you are at it go find who the members were on the commission for IEC 555-2. [Hint, they work for power companies.]
Then go find who made campaign contributions to those politicians that pushed the standard into being law. [I won't be surprised.]

.

[Per Hansson]

Re: PC Restarting/ Shutting off abruptly.

The increased current from the reactive power wastes heat for a few miles of copper until it hits the power factor correction capacitors on the power lines.

That is actually not possible, the harmonics created by SMPS are so complex that the power companies can not filter them like they can for a normal linear loads...
Quoting wikipedia; This presents a particular problem for the power companies, because they cannot compensate for the harmonic current by adding simple capacitors or inductors, as they could for the reactive power drawn by a linear load. Many jurisdictions are beginning to legally require power factor correction for all power supplies above a certain power level.

The fact is that a SMPS without PFC only draws current when the sine wave voltage is above the voltage of the primary capacitors
This creates an "ebb and flow" condition and is what PFC fixes
It makes the SMPS draw a linear load, which has other benefits too
If for example you have a UPS it will not like this "ebb and flow" consumption, you will infact most likely overload a 1kVA UPS with a SMPS without PFC consuming only ca 400w of power, source; (scroll down to UPS Nonlinear Loads) http://powerelectronics.com/mag/powe...tem/index.html


PCBONEZ; Why do you just make up comments when you have nothing to disprove the actual facts presented to you?
Nobody in this thread said "The claim appears to be that PFC makes the rest of the system more efficient."

And no, the test does not proove that watt meters show bogus data

The reason it uses less power with PPFC on is simple. Supplies with PPFC do not have a thermistor so I wired the switch to switch off the thermistor when the PPFC transformer is switched on. A thermistor is less efficient than a PPFC transformer.

Since I won't be here much and PFC has been around a long while now, why don't you boys use the time and go find one single instance or a power company switching to smaller generators, transformers, and wire.

Why in the love of god would they switch to new smaller equipment?
Of course in NEW designs they may take into account the better power factor they get from their consumers, but what would make you think they would pull down perfectly working equipment just to put up less capable equipment?

While you are at it go find who the members were on the commission for IEC 555-2. (Hint, they work for power companies.)
Then go find who made campaign contributions to those politicians that pushed the standard into being law. (I won't be surprised.)

And this is supposed to be surprising how?
In any case the power companies save money, of course they want this legalization, it would be either that or to start charging consumers for poor power factor (Companies get to pay for their power factor consumption as it is, so it just a form of "good faith" that consumers don't have to)

[everell]

Re: PC Restarting/ Shutting off abruptly.

Now that we know power factor correction does not improve the effeciency of the power supply.......and now that we know pfc only adds to the parts count of the power supply..... and consumes additional power........and generates extra heat......now lets ask some questions directly related to power supply design and troubleshooting.

The APFC circuit boosts the DC voltage to about 385 volts. I was looking at the data sheet for a CM6800 chip.......their explanation suggested a target voltage of 385 volts.

In the US, using 115 VAC, multiply by 1.4, and the voltage delivered to the mains cap is 161 volts DC. That is what I normally measure. So to bring it up to 385 volts means that the APFC circuit will have to generate enough power to boost the 161 volts to 385 volts, which is 324 volts.

In the UK, using 230 volts, multiply by 1.4, and the voltage delivered to the mains cap is 322 volts DC. To bring it up to 385 volts requires an additional 163 volts.

This means that in the US, twice as much voltage will need to be generated. Once the 385 volts has been generated, the PFC circuit must maintain that voltage. Since the load current to the power supply should be the same in either country, that means that APFC circuits in the US will have to generate TWICE as much power. That means twice as much heat for a given circuit.

The efficiency of the APFC circuit determines how much power is delivered to the load and how much power is lost as heat. The APFC circuit usually has one or two FET transistors, a large diode, and a toroid coil. The transistors and diode are attached to a heat sink. So my question is.......how much heat is that toroid coil developing - what should we expect to be normal?

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

Only have time to skim this right now.
At least everell isn't lost...

severach and hansson [as per quote] say no PFC is less efficient and [get this] "The thermistor does it"

AAAAAAAAAAAAHHHHHHHHHHHhhhhhhhhh hahahahahahahahahaha
hahahahahahahahahaha hahahahahahahahahaha

#1: Unless there is an over-load condition, a thermistor dissipates something like 1/8 watt,, which is why they can heat-shrink them without causing a fire.
#2: APFC PSU's -do- have thermistors unless they are some crap unit.
#3: The is NO WAY a thermistor is going to dissipate more heat than two+ transistors, a diode pack, an IC, a coil, AND A THERMISTOR.

APFC in a PSU with a 500w load will dissipate between 20 and 25 watts. [And a thermistor around 1/8w.]

.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

That is actually not possible, the harmonics created by SMPS are so complex that the power companies can not filter them like they can for a normal linear loads...

- Wrong.
- Totally possible.
- The equipment has existed since the at least the 1950's.

Passive PFC [which is enough to make things 'IEC (whatever) compliant'] is nothing more than a band-pass filter.
- EASY to build them in 'industrial' sizes.
- There are at least two vendors in Phoenix that sell whole house PFC units.

But the power companies don't want to pay for the equipment to do it.
FOR DECADES they didn't want to pay for it.
- Which clearly shows the power savings wasn't worth it..

They were much happier to create a standard and line politicians pockets to make that standard law - thereby forcing consumers to foot the bill for their 'upgrade'.
[All the while hiding the fact that the higher cost of PSU's and other consumer electronics is solely to save THEM money.]

PFC IS NOT ABOUT "GREEN".
It's about power companies lining their pockets.

.

[PCBONEZ]

Re: PC Restarting/ Shutting off abruptly.

I think I've seen the "it will save your UPS" line twice now...
~ Yeah RIGHT!

Maybe from a pure theory standpoint,,, just like from a pure theory standpoint using the wiper blades reduces gas mileage [or better yet, reduces the life of your alternator.]

UPS are designed to be connected to PSU's.
They can handle it, that is what they are designed for.
I have several that are 10-12 years old that spent the bulk of their life on non-PFC PSU's and they still work fine.

And then there is that:...
UPS units already have PFC,, so if you are using a UPS then you already have PFC between your PC and the power company,, The PC doesn't need it too.

And... [This is pretty well known for years now. I'm surprised someone that touts himself as a tech writer isn't aware of a major safety issue like this.]
- If you use a PFC or APFC PSU connected to the more common UPS units that don't output a true sine wave then you are at risk of blowing out the first stage of the PSU or even causing a fire. The voltage across the input caps will be pushed high. Sometimes WAY high.
- There was a thread right here on BCN that went into this in detail complete with O'scope traces 2 or 3 years ago. [Only good thing that guy ever did here.]
- Since then Silverstone ran tests with one of their SST-OP700 PSUs on various UPS units. The voltages across those caps [which are often 400v caps] were 408 to 497 volts with various non-sine wave UPS units. [See PDF below.]

With that kind of UPS you damned well better not have PFC!
[Unless your goal is to attract firemen...]
.

[Per Hansson]

Re: PC Restarting/ Shutting off abruptly.

PCBONEZ; you say you only have time to skim this
I think that is a big reason for the misunderstandings in this thread

For example no-one has claimed that APFC powersupplies are more efficient in this thread, but you keep on saying we are wrong, and then reiterating it is no more efficient?

In your first post today for example you say me and severach are wrong
And the important part is that you say severach is claiming passive PFC to be less efficient
In actuality he found it to be _more_ efficient (which is the first time in this thread anyone has claimed PFC to be more efficient, surprising atleast both him and me)
He said the reason was he removed the thermistor, and in it's place put a Passive PFC transformer
The efficiency improvement was only 4 watts, hardly something to get overworked about (and the reason being as he said that the thermistor is gone from the circuit now)
Then you go on about APFC, but it was not an APFC circuit that severach added, it was a Passive PFC circuit

----
Next we have your other post for today
I atleast quoted wikipedia when I said that power companies "cannot compensate for the harmonic current by adding simple capacitors or inductors, as they could for the reactive power drawn by a linear load."

You say otherwise, and conveniently leave no source for the claim
But in any case, even if they can filter it at their side they have already lost
Because the apparent power must also be transmitted over the powerlines, which along with the transformers, fuses etc must be built to handle this load
And it should be obvious then that the transmission losses increases
I.e. the extra apparent power transmitted over the powerlines will result in a higher transmissionloss than if the filtering was on the consumers side

As for your last post I'm well aware of the issue with stepped sine wave UPS'es and the overloading of the primary capacitor
I made many replies to that thread which brought it up on JG, linked at the start of this thread here on Badcaps I believe

[everell]

Re: PC Restarting/ Shutting off abruptly.

pcbonez: I greatly appreciate your comments from your experience working with the power company - it DOES give us a better picture of the overall process. I also appreciate the thoroughness with which severach approaches the practical side of repairing power supplies. His report on how the Bestec 12E failed was excellent....I learned a lot from him.....even had to admit I was wrong about some things.

I feel that MOST of the audience here on badcaps will be involved with repair of failed power supplies with APFC. I doubt that very many of the passive PFC coils will fail! One of the first things we have learned....and is well documented here on badcaps...... is not to use non-sinosoidal UPC on computers with APFC on power supply. BOOM!

My concern is how much of a problem APFC will be in the US. I tried to show that the added power and heat is about twice that of the same power supplies in UK. Added heat means reduced lifetime for capacitors in the power supply. Possibly another BOOM.

I was given a power supply to "play with" and repair. A Delta with active PFC. Report from computer shop was that customer came in one morning to a room full of smoke, computer still on. When I looked at it, fuse was blown, the APFC transistors were shorted, the two toroid coils were badly burned, and the capacitor across the bridge rectifier output was split open. See attached pictures.

Now for some questions. Was customer using UPS with this computer? Don't know. But this computer ran several years without trouble.

Was this failure due to a surge that occurred overnight? Don't know.

The "mains capacitor" was 270 uF/450 volts. When the APFC is on, the measured voltage across this capacitor is 403 volts DC. Considering the peak signal being filtered from the PFC circuit.....is this capacitor voltage rating sufficient? I have seen some power supplies with only a 400 volt rated capacitor (a couple of them were bulging). Also, the APFC circuit is switching at a frequency of about 80 khz. Are the capacitors used as the "mains" able to handle the esr from the APFC switcher?

And what about the capacitor across the output of the bridge rectifier - why did it split open. Its value was 105 (1 uF) at 450 volts. How much signal voltage is being backfed from the APFC circuit?

As you can see, APFC leaves me with more questions than answers when it comes to the more practical side of repairing the power supply.