Gigabit and 100 megabit LAN mixing

[tom66]

I am setting up our new house with a media server.

Downstairs there will be a media server/PC in another room and a long HDMI lead+optical audio to the TV+amp. This will have 5 or 6 x 250GB SATA-II 7200RPM HDDs so will be very loud (hence why it's in another room.) The HDDs will probably be in RAID-5 giving me performance and single-drive redundancy @ 1TB~1.25TB, it will only be storing media files so more redundancy is not critical. The media server will probably act as a NAS of some kind.

I plan to network this PC with gigabit ethernet to a gigabit switch (<2m away.) The gigabit switch has five ports. One port will be for the PC. The other four ports will go to various networks: one to the internet (going through the ISP-provided WiFi router), one to the 2nd floor rooms (2~4 PCs), one to the 3rd floor rooms (2~4 PCs), and one spare, probably for a Raspberry Pi or some media sink for another room. Each floor has its own 100Mbit switch (I've got a few 8 port ones spare.)

My main question is, will I be able to achieve a full 400Mbit throughput (50MB/s), barring HDD limitations, with a gigabit switch connecting to four 100Mbit switches? I plan to be able to sink 25~50Mbit per PC from this server, up to eight PCs active at any one time, which easily allows for compressed 1080p video streaming. Hence the RAID so simultaneous access isn't difficult. Ideally, it would also be simultaneously be able to play some of its own content onto the TV! I know it's overkill, but that's how I roll. I'm going to try and source a fast processor for it, perhaps an older generation Core 2 Quad. Maybe even a Xeon? (Suggestions on ideal processors for a streaming server like this are appreciated.) The OS will be Windows XP 64-bit or maybe Windows 7 64-bit if I can find a genuine copy (I've got an old OEM disk from a friend for XP, but not one for 7.)

Any advice appreciated.

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

A switch is a switch, it won't care if the ports are 100mbps or 1gbps, it will do full speed on all ports provided the cables are good.

I doubt you'd sustain high read speed if several pcs read data from those drives even if they're in raid.

I wouldn't waste my time with 250 gb drives, they're just too small and old

[tom66]

Re: Gigabit and 100 megabit LAN mixing

I just happened upon a few 7200RPM 250GB drives, so I'm keeping them. They're not the fastest in the world, that's for sure, but I'm sure they'll be able to do at least 20 MB/s each which is no problem, should give me a peak of 100MB/s on RAID, in ideal cases. Scattered files will be a performance hit of course. I wanted to keep all of the drives the same size so I'm going to try and source some more of them, but they will probably be mixed brand used drives. As it's a singly redundant setup, a failed drive isn't a critical problem.

I did plan on using cheap eBay cables () but I may go "premium" on the few-metre-long gigabit cable going to the gigabit switch, as everything else will be 100Mbit and in my experience even the cheapest eBay cables are quite capable of doing that.

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

Don't bother getting cables from eBay...

You have amazon uk or local stores.

I can buy 2m cables locally here for a dollar a piece, 3m patch cables for 1.5$ and 5m cables for 2 dollars (in local currency)
If you want i can buy some locally and mail them to you, but with 3-5$ in postage, it's gonna end up the same price.

On amazon uk they're a bit more expensive but not by much

http://www.amazon.co.uk/Belkin-Cat5e...919219&sr=1-64

Cat5e will do gigabit just fine, especially since you have short distances.

I have a tool to install rj45 jacks on network cables since the university times when i was network administrator for a year or so, and I've used to make my own cables but lately I didn't bother anymore.

Cheapest meter of cable is about 15-20 cents a meter, two jacks are about 10 cents... a 2m patch cable with molded jacks and everything is a bit over a dollar. I just added 3 patch cables to my latest order when I got a router

[tom66]

Re: Gigabit and 100 megabit LAN mixing

Local stores here charge rip-off prices. £30 for a 20 metre 100Mbit cable that sells at around £2~£3 online. Amazon are about the same price as eBay but what makes you think they are any better than the eBay ones?

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

The one I linked to is Belkin, which is a relatively good brand, known.

With amazon uk, you can return them no question asked.. well, if you choose the cables sold and shipped by amazon, not one of the sellers using their warehouses to ship or something like that.

With 2-5m cables, any cable will work about the same bandwidth/speed wise, the difference between manufacturers is usually in the terminations, the jacks. A no-name/chinese cable may use jacks of less quality which - in time - due to heat cycles and other factors may cause the wires inside the jacks to come loose. Keep in mind the wires in the jack are usually fixed to those pins simply by friction - when you install the jack, the tool presses on those pins and the pins cut INTO the wire like a knife, and that's how the connection is made. So if the jack is of poor quality or the copper in the jack is crap, the pins can get loose.

When I did net admin, in a campus building the budget was low so we tried to save money by not using ready-made patch cables or patch panels and the jacks turned out to be too poor quality - after about 7 months with the switches heating the room to about 27c all the time, maybe 3-5 cables out of 100 or so got loose wires in the jacks. I just cut the jacks off and installed new ones.

20 meter cables aren't that cheap or shouldn't be cheap, mostly because of the weight.

Local stores gauge you because they can, but online stores kinda have a justification: they're usually too big to fit into a standard A4 envelope or a small packet, and they're heavy so they go into another category of packages where the shipping is slightly more expensive.

Amazon doesn't care usually because they ship so much they just make contracts with companies where they promise they will ship a certain amount of cubic meters of packages and a number of packages in return for low shipping costs. Weight is less important for them.


In UK you should also have ebuyer.com , aria.co.uk (from what I remember) and I think and I'm sure there are some stores that are more focused on connectivity (cables, connectors, stuff like that)

[tom66]

Re: Gigabit and 100 megabit LAN mixing

I do need some ~10m cables for the upstairs rooms, and 20m at least for each floor. Would you have any suggestions for reliable ones? Belkin want around £8 for 15m. I'm on a budget...

[tom66]

Re: Gigabit and 100 megabit LAN mixing

Hmm, not too bad for 10m...
http://www.ebuyer.com/25535-belkin-c...a3l791b10m-ylw

I'll see how the budget works out. Most of the money was going on the NAS/media server.

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

No, sorry, I don't really know what else to suggest when it comes to patch cables.

If you need more than a couple or so cables of that length, get a crimping tool and make your own cables, it's cheaper that way.

A good crimping tool is at least 15-20 pounds, a perfect one can get close to 100 pounds, but for a few cables a cheaper one would work...

Basically, the ideal crimping tool is one that presses on those contacts straight down, and not from a slight angle like what would happen if the tool is shaped like pliers.
But those tools are quite expensive

Here's something that looks OK for the price:
http://uk.farnell.com/duratool/d0012...het/dp/1447420
http://www.amazon.co.uk/s/ref=nb_sb_...ATOOL+-+D00125

Again, it's not the best type of crimping tool but it would work for a few jacks.

But the big problem is the cables ... I searched amazon uk for some good cables and other than 100 meters roll made by Belkin at 50 pounds, everything was pretty much crap.
The cheapest cables are CCA (copper clad aluminum), not really solid core copper, and these CCA cables are not great. They may do 1 gbps but I wouldn't bother with them.

You really should search for some stores that sell 305m spools and are willing to sell you 100 meters or something like that, and you should find good quality cable at something like 20-25 pounds for 100 meters.

RJ45 jacks are really cheap.. You can't really tell from pictures what's better or worse.

These seem to have good reviews:

http://www.amazon.co.uk/RJ45-Crimps-...940317&sr=1-10

These also look good and considering they're (supposedly) rated cat6, they may be of better construction:

http://www.amazon.co.uk/Cat6-RJ45-Cr...940317&sr=1-18

[tmiha71]

Re: Gigabit and 100 megabit LAN mixing

Do not know, if still is the same, in the past (switches which I looked at, or were that devices - HUBS ??, can't remember), you will have 100 Mbit on all your network (speed of the slowest device, including - 1Gb link will drop to 100Mbit, check it in manual ...)
Average bit rate for "MPEG I" was 1.5Mbit/s, if by today's standards it is raised by factor 10, you'll have approx 6 streams, which (100 Mbit ~ 10 Mbyte) can be feed by very old hard drives (even 10 years old hard drives /7200 rpm/ have ~ 20Mbyte RANDOM READ, and video is SEQUENTIONAL READ)...

Not sure what do you mean by adequat processor, today is everything DMA driven, CPU sets parameters for different DMA tasks
- read from HD
- writting to network card
etc...
Even Pentium generation had no trouble feeding 100Mbit ( without any DMA )... Today's buzz word is CONSUMPTION...
I would look at any dual core with minimum consumption, that probably means with smallest cache available, but wouldn't go under 512k per core, frequencies above 2.5 GHz would ignore too)...

If you build RAID (other than mirroring), and mix VIDEO with other content, you will pay performance penalty...

At first it looks like each HD should be on it's own interface (in the past it was 1 HD on one IDE channel, probably the same for SATA, should be checked if that means 1 hard drive per SATA chip yaaak ) - for best performance...

For needed cables, permissible lenght, number of max. hops, manual of network devices should be consulted...

Just few notes, so called "internet knowledge"... Hope it helps (somehow)...

[tom66]

Re: Gigabit and 100 megabit LAN mixing

I need a gigabit for the link between the switch and the PC, but I can spend extra money on that; it's only going to be a metre or two long. The rest (I have four rooms at 10-15m at least plus two floors with 20m per floor, each floor on one port of the gigabit hub) will be using conventional Cat5e, 100Mbits max, less than 10Mbits average. I think my workplace may have such a crimp, I may be able to borrow it for a night and make a few cables, but I wonder if it is worth it.

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

Hubs take everything they receive through a port and broadcast everything to all the ports.

Switches are smart enough to recognize what's behind each port of the switch by memorizing the MAC addresses, the IPs, etc. Without mentioning the "fineprint", they take packets coming from a port and only move the data to the port the data was meant to go through.

Yes, hubs can slow your 1gbps connection to 100mbps simply because they broadcast the data through all ports. So you can't upload at 1gbps and have that 1gbps squeezed through each 100 mbps port.

In contrast, with a switch, 4 computers on 100mbps can request data from your PC linked at gigabit speeds, the pc sends 400 mbps to the switch and the switch will split the packets and push them through the proper ports automatically.

A DVD (vobs etc) has about 10-14 mbps bitrate
A h263 (xvid, dvd rips, 1-2 cd rips) generally have about 1000-1500 kbps or 1-1.5 mbps
A h264 (mp4, bluray rips) can have various bitrates depending on resolution and quality:
* a tv show like jay leno, conan, news etc is usually about 1 mbps ,
( a 720p is about 3-5mbps,
* an 1080p rip is about 10-15 mbps (10-12mbps video, 1-3 mbps audio)
* a bluray/hd-dvd - disc copu, not recompressed is about 25-30 mbps, some go as high as 40 mbps

Processor doesn't have to be fast, even a core2duo/dual core amd would be enough.
The problem will be more about I/O and disk seeking.
The 250 GB drives will read at 20-50 MB/s as long as you read one file. If you go and read 2-3 files at a time, the performance goes down the crapper and you'll see 3-7 MB/s.. maybe.

In comparison, 1-2 TB drives nowadays have data so densely packed that they'll read at 90-120MB/s and with 2-3 simultaneous reads they'll still do 10-30 MB/s.

Having the drives in a RAID5 would improve speed for one file as the data is read from 3-5 drives simultaneously and recombined, but if you go and read 2-3 files at a time, all drives will have to seek and their performance will simultaneously go down.

Will you have 100 MB/s when streaming/copying a single file? Yes, maybe.
Will you have 10-15 MB/s when streaming 2-3 videos at same time, or when you copy a file to the disks while streaming 1-2 files to some computers? Maybe but I'm leaning towards even less speed.

Would be a different thing if each drive would be independent, that way if you're lucky each file streamed would be on a different drive, but then you wouldn't get the speed improvement of reading same file from several drives.

What could help would be plenty of ram, to cache data as it's streamed -aka when you start to stream a file, the OS or software on NAS reads at faster speed and buffers a chunk or all file in ram so that if it happens that other streams are started, then there's no IO issue.

[Uranium-235]

Re: Gigabit and 100 megabit LAN mixing

not all switches have full port x 1gb throughput. I'd think a small switch would but some larger ones max out on throughput. There is a lot of 100mbps switches out there that actually have a max of 200mbps throughput

mariushum is right, buying cable by the bulk and making your own is the best way to go. If its a long backbone cable i'd suggest cat6 over 5e

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

As long as it's solid core Cat 6 no problem, multi strand cat 6 is a bitch to crimp.

Cat5e really is enough for gigabit, I've used FTP cat5e cable (like utp cable but has a solid steel wire through it and each pair is separated by an insulator inside the cable for less noise and to make the cable stronger) to connect two buildings.

The cable was about 112 meters, going through a long corridor, then up the building wall, then across a yard and through the roof of the other building... even though it was over 105 meters which is the maximum in theory, it did 1 gbps without packet loss between the buildings.
Though the switches were kinda expensive (for that time) 48x100mbps+2x1gbps switches, allied telesyn.

The moral of the story is cat5e is good enough for 20 meters, inside a house. Just get good cable, solid core if you plan to crimp it yourself as it's easier, and make sure it's not cca (copper clad aluminum).

[tom66]

Re: Gigabit and 100 megabit LAN mixing

The gigabit switch I am getting is 5Gbps "fabric speed", I assume this means maximum 5Gbps all ports active. The two 8 port switches I have are Netgear and some unknown brand one, but they both use the same Realtek(?) chipset, and the Netgear is rated at 800Mbps combined, so I hope both will be capable of 800Mbps.

May have to reconsider the HDDs then... perhaps using just two or three 500GB drives would be better than five or six 250GB drives? My motherboard has six SATA RAID capable ports (hardware RAID.) 1TB is out of my league at the moment. I have a 500GB in my desktop. I may put in two 250GB in RAID to replace it, then buy a few more 500GB drives for the media server. Of course, 500GB is more expensive, which makes single drive failures more expensive to repair. (We're trying to reduce expenses.)

I'm now also considering whether to make the NAS independent, or not... because there are very few good NAS programs for Windows whereas I can get FreeNAS which is open source and high performance, but runs on FreeBSD. But then I need an independent computer for the TV (XBMC runs great on loads of OSes but I'd also like to run Windows games), which is a hassle. I think if I just used Windows/Samba shares I would take a performance hit because XP/7 aren't server optimised OSes.

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

Here's some great switches cheap tom :

HP ProCurve 2626

http://www.ebay.co.uk/itm/HP-ProCurv...item4ac2f39454

9.6gbps fiber, 24x100, 2x1gbps, 2 ports for extension, serial console, management etc (if you get it make sure it's not passworded/get the management password)

ALIED TELESYN AT-8350GB FAST ETHERNET SWITCH 48 PORTS + 2GBIC

http://www.ebay.co.uk/itm/ALIED-TELE...item27d11e6124

I actually worked with one of these or a very similar model, 48 100mbps , 2x1gbps , management (serial port/telnet), iirc about 17gbps fabric, worked great

Netgear-FS526T 24 + 2x1gbps

http://www.ebay.co.uk/itm/Netgear-FS...item1e792630fa

8.8 gbps fabric , search for reviews for this one, spec wise seems a bit weaker than the others but still overkill for a home.

[tom66]

Re: Gigabit and 100 megabit LAN mixing

Damn that is cheap. I think I may get that ProCurve (it's quite close to me.) It would definitely make everything a lot easier if I had one master switch for everything... on the other hand, I would need to get a lot more cable, but that's not a major problem. Perhaps simply having 24 downstairs ports is a good idea, with a gigabit-gigabit link between two PCs (perhaps a media server & media PC.) Decisions, decisions...

Anyone know if it's a bad idea to connect two 100Mbit cables to one switch from the same master switch? Would I be able to get 200Mbit data rate or would only one end up being used? So now I'm thinking of running two cables to each switch allowing me to get a very high speed interconnect. I'm massively over-engineering this because I may end up doing something crazy (I mean insane) like trying to stream 4K video. If I ever find a display to work with that. Or just fast disk-disk copy between machines, I have two SSDs in my current desktop (240GB total.)

[mariushm]

Re: Gigabit and 100 megabit LAN mixing

Tom, sorry, I don't know if that procurve has port trunking (that's the term), you'll have to check the user guide/manual.

The Allied Telesyn switch, if I remember correctly - my memory is sketchy, I've stopped doing network admin. about 2-3 years ago - did support trunking of 2 and maybe even 4 ports, but it doesn't work like you think. It may have had standard 2 port trunking and an option to use 4 100mbps ports to stack with other allied telesyn switches, if you somehow lost the backplane cable that does 17 gbps between the switches or you had a cheaper alied telesyn switch without that stacking connector or gigabit ports.

You have to configure both switches to choose those ports to do trunking, or your switch must be set for trunking and the network card must also be smart enough (and the driver/software it comes with has to support it).

There are intel workstation cards with 2 ports and server cards with 4 ports that do trunking well but they're not really worth it. Some single port intel workstation cards had software that let you combine two cards to work as one, with port trunking, but I never tried it.

You may get them cheap but most of them are pci-x (they'll work on pci but with the 133mb/s pci bus limit):

http://www.ebay.co.uk/sch/Internal-N...s&_stpos&gbr=1

it's cheaper to just get a 4-5 x 1gbps switch and use the network card that's onboard and get better speeds.

btw... those intel pro 100 mbps single port cards and the hp cards (they're intel), on pci even, are amazing. They were better than any onboard 100mbps network cards but these days the onboard gigabit chips are quite capable.

Can't say anything about that Procurve, but I've worked with those Allied Telesyn switches ... had 2 x 48+2 and 1x24 all stacked with their proprietary cables in a building with 4 levels and about 100 rooms and linked like i said through a gbps port to other buildings, they worked really great.

They were about 3-400 euro back then... probably about 500-800 dollars/euro in today's prices.

[tom66]

Re: Gigabit and 100 megabit LAN mixing

This is all very useful information, thanks!

I will need to decide on what set up to use but it'll probably be based around some large port count switch with at least one gigabit port, preferably two or more.

Regarding the ProCurve is the management password permanently set, is there no way to remove it (e.g. a battery inside the unit that can be disconnected or a sequence of commands?) The other units could also be used, the Allied Telesis looks nice (free postage is attractive) and sounds like it has a good personal review from yourself.

Also, the motherboard I am using has integral gigabit ethernet, so I presume the PCI limit won't apply here (I guess it is using PCI express as it has a few PCI express ports.)

[Mad_Professor]

Re: Gigabit and 100 megabit LAN mixing

This is what I use for my home network, it has port trunking and vlan support and bunch of other things.

http://www.dlink.com/us/en/support/p...ombo-sfp-ports

I only use it for the vlan and power saving features. It's a great switch I've had it since may 2011, I hardly had to do anything since it's initial setup and maybe fooling around with it.

I only paid 200 for it brand new vs the 400 newegg wanted for it.

as for integrated gigabit nics if it's a newer 775 or am2 and up it will be using pci-e, but manufacturers like to cut cost so it depends on what chipset you have.

also build a fileserver using centos then install xbmc or use mythtv get acouple of cheap tuners and you can watch record and time shift tv.