Entry level gigabit switches for home use
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Originally Posted By: OVERK1LL
Originally Posted By: firemachine69
I think he's going by what the connection details in Windows is telling him...
That's kinda what I was thinking as well.... No actual throughput testing done...
Yes, I am going by what my computer tells me. I'm just a hack and lack the knowledge to be a computing professional. Alas, it is only a home PC dedicated to iTunes, Quicken and the interweb.
I'll try and do a full battery of tests next time.
Originally Posted By: firemachine69
I think he's going by what the connection details in Windows is telling him...
That's kinda what I was thinking as well.... No actual throughput testing done...
Yes, I am going by what my computer tells me. I'm just a hack and lack the knowledge to be a computing professional. Alas, it is only a home PC dedicated to iTunes, Quicken and the interweb.
I'll try and do a full battery of tests next time.
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Originally Posted By: Volvohead
A single bend exceeding spec, or laying a run in the wrong location (too near a magnetic field or parallel to a mains line), or a sloppy termination is enough to blow it for the entire LAN. All the TCP tweaking in the world won't fix a sloppy punchdown.
If you're tweaking TCP to fix the cause of a network speed issue and you haven't checked for frame errors, collisions and crc errors, you're wasting your time. (My experience is that many network speed issues are caused by duplex mismatches, which usually show as ridiculously high numbers of collisions in relation to the number of packets transmitted).
On the other hand I still haven't found anyone who can tell me how, with Windows XP, to find out how many collisions the network card has seen. My solution is to boot the PC with Knoppix and use a real OS to find out.
BTW I run gig on cat5. No "e".
A single bend exceeding spec, or laying a run in the wrong location (too near a magnetic field or parallel to a mains line), or a sloppy termination is enough to blow it for the entire LAN. All the TCP tweaking in the world won't fix a sloppy punchdown.
If you're tweaking TCP to fix the cause of a network speed issue and you haven't checked for frame errors, collisions and crc errors, you're wasting your time. (My experience is that many network speed issues are caused by duplex mismatches, which usually show as ridiculously high numbers of collisions in relation to the number of packets transmitted).
On the other hand I still haven't found anyone who can tell me how, with Windows XP, to find out how many collisions the network card has seen. My solution is to boot the PC with Knoppix and use a real OS to find out.
BTW I run gig on cat5. No "e".
OVERKILL
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Originally Posted By: tmorris1
Originally Posted By: brianl703
Audio/video streaming works fine even on 10 megabit, for DVD quality mpeg2 video. There's no reason to go to gigabit just for that.
You are probably right, but if all the equipment can do it why not?
Most of it cannot. There was a NIC test done not all that long ago and most Gigabit NIC's that are not server-grade will not actually push/pull at gigabit speed.
Until recently, most computer hard drives wouldn't read or write at that speed either! It has only been since platter density has gone through the roof that we have started seeing consumer drives with throughput above 100MB/sec......
Originally Posted By: brianl703
Audio/video streaming works fine even on 10 megabit, for DVD quality mpeg2 video. There's no reason to go to gigabit just for that.
You are probably right, but if all the equipment can do it why not?
Most of it cannot. There was a NIC test done not all that long ago and most Gigabit NIC's that are not server-grade will not actually push/pull at gigabit speed.
Until recently, most computer hard drives wouldn't read or write at that speed either! It has only been since platter density has gone through the roof that we have started seeing consumer drives with throughput above 100MB/sec......
Originally Posted By: OVERK1LL
Most of it cannot. There was a NIC test done not all that long ago and most Gigabit NIC's that are not server-grade will not actually push/pull at gigabit speed.
I can't get more than 300mbps out of my gigabit NICs.
Quote:
Until recently, most computer hard drives wouldn't read or write at that speed either! It has only been since platter density has gone through the roof that we have started seeing consumer drives with throughput above 100MB/sec......
Do you think replacing my 80GB laptop drive with a 320GB drive would give better throughput? The 80GB drive seems to max out at 25MB/sec.
Most of it cannot. There was a NIC test done not all that long ago and most Gigabit NIC's that are not server-grade will not actually push/pull at gigabit speed.
I can't get more than 300mbps out of my gigabit NICs.
Quote:
Until recently, most computer hard drives wouldn't read or write at that speed either! It has only been since platter density has gone through the roof that we have started seeing consumer drives with throughput above 100MB/sec......
Do you think replacing my 80GB laptop drive with a 320GB drive would give better throughput? The 80GB drive seems to max out at 25MB/sec.
Originally Posted By: brianl703
I can't get more than 300mbps out of my gigabit NICs.
But what is the limiting factor? The NIC on the local end? The NIC on the remote end (second machine in the LAN)? The switch? The Cat5 cable that you're using? Or maybe the PCs are not capable of reading/writing data to HDD fast enough?
I can't get more than 300mbps out of my gigabit NICs.
But what is the limiting factor? The NIC on the local end? The NIC on the remote end (second machine in the LAN)? The switch? The Cat5 cable that you're using? Or maybe the PCs are not capable of reading/writing data to HDD fast enough?
That 300mbps is reading/writing an 8MB file, so it's not an HDD limitation, as the machines have more than enough memory that the 8MB file is cached in the machine's ram.
It's not the cat5 cable. There are no errors or retransmits, and thruput is still the same when using a cat5e cable. (The cable diagnostic into the Broadcom NIC I have says the cat5 cable is fine, in any case).
It could be the switch. I haven't tried using a crossover cable to connect the NICs directly together. I expect, though, that the results will be the same.
The one thing I think may make a difference is to enable jumbo frames.
It's not the cat5 cable. There are no errors or retransmits, and thruput is still the same when using a cat5e cable. (The cable diagnostic into the Broadcom NIC I have says the cat5 cable is fine, in any case).
It could be the switch. I haven't tried using a crossover cable to connect the NICs directly together. I expect, though, that the results will be the same.
The one thing I think may make a difference is to enable jumbo frames.
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Originally Posted By: brianl703
Originally Posted By: OVERK1LL
Most of it cannot. There was a NIC test done not all that long ago and most Gigabit NIC's that are not server-grade will not actually push/pull at gigabit speed.
I can't get more than 300mbps out of my gigabit NICs.
Quote:
Until recently, most computer hard drives wouldn't read or write at that speed either! It has only been since platter density has gone through the roof that we have started seeing consumer drives with throughput above 100MB/sec......
Do you think replacing my 80GB laptop drive with a 320GB drive would give better throughput? The 80GB drive seems to max out at 25MB/sec.
It would. The higher platter-density drives are MUCH faster.
In regard to the Gigabit NIC's, here's some food for thought:
-The classic PCI BUS is only capable of 133MB/sec
So, if you have a gigabit NIC PCI card, you are likely to completely saturate the BUS. Remember, it is being shared with your video card, sound card, IDE controller....etc.
On the other hand:
-The PCI-E 1x 1.x interface is capable of 250MB/sec
-The PCI-E 1x 2.0 interface is capable of 500MB/sec
So the chipset should not be a limiting factor on PCI-E systems.
Originally Posted By: OVERK1LL
Most of it cannot. There was a NIC test done not all that long ago and most Gigabit NIC's that are not server-grade will not actually push/pull at gigabit speed.
I can't get more than 300mbps out of my gigabit NICs.
Quote:
Until recently, most computer hard drives wouldn't read or write at that speed either! It has only been since platter density has gone through the roof that we have started seeing consumer drives with throughput above 100MB/sec......
Do you think replacing my 80GB laptop drive with a 320GB drive would give better throughput? The 80GB drive seems to max out at 25MB/sec.
It would. The higher platter-density drives are MUCH faster.
In regard to the Gigabit NIC's, here's some food for thought:
-The classic PCI BUS is only capable of 133MB/sec
So, if you have a gigabit NIC PCI card, you are likely to completely saturate the BUS. Remember, it is being shared with your video card, sound card, IDE controller....etc.
On the other hand:
-The PCI-E 1x 1.x interface is capable of 250MB/sec
-The PCI-E 1x 2.0 interface is capable of 500MB/sec
So the chipset should not be a limiting factor on PCI-E systems.
Originally Posted By: OVERK1LL
It would. The higher platter-density drives are MUCH faster.
That's what I figured.
Quote:
In regard to the Gigabit NIC's, here's some food for thought:
-The classic PCI BUS is only capable of 133MB/sec
Yes, the gigabit cards I'm using are PCI. The server gigabit cards all seem to be PCI-X (64 bit, 66Mhz PCI). Yes you can use them in a regular PCI slot but I'm not sure they'll be much faster than a regular PCI gigabit then.
In theory, with busmastering, the disk controller should be able to talk directly to the gigabit controller so the data needn't be copied twice (from the disk controller to memory and then from memory to the gigabit card).
It would. The higher platter-density drives are MUCH faster.
That's what I figured.
Quote:
In regard to the Gigabit NIC's, here's some food for thought:
-The classic PCI BUS is only capable of 133MB/sec
Yes, the gigabit cards I'm using are PCI. The server gigabit cards all seem to be PCI-X (64 bit, 66Mhz PCI). Yes you can use them in a regular PCI slot but I'm not sure they'll be much faster than a regular PCI gigabit then.
In theory, with busmastering, the disk controller should be able to talk directly to the gigabit controller so the data needn't be copied twice (from the disk controller to memory and then from memory to the gigabit card).
I just got a gigabit PCI card for my main PC. I tried transferring large files (3+ GB) between it and my HTPC which has an on-board gigabit port.
Copying files from my PC to HTPC, I am getting steady 83 MB/s (664 Mbps). That's with two switches in-between - a main 3Com one and a small Rosewill one. But copying files the other way (from HTPC to my PC), I am only getting about 45 MB/s (360 Mbps). Both PCs use SATA drives. Curious why the difference...
Are there any free windows (7) utilities out there that can diagnose the number of dropped frames, etc.?
Copying files from my PC to HTPC, I am getting steady 83 MB/s (664 Mbps). That's with two switches in-between - a main 3Com one and a small Rosewill one. But copying files the other way (from HTPC to my PC), I am only getting about 45 MB/s (360 Mbps). Both PCs use SATA drives. Curious why the difference...
Are there any free windows (7) utilities out there that can diagnose the number of dropped frames, etc.?
absolutely get the jumbo frame on all the cards and switches. gigabit is useless (or near useless) without jumbo frame.
Originally Posted By: brianl703
In theory, with busmastering, the disk controller should be able to talk directly to the gigabit controller so the data needn't be copied twice (from the disk controller to memory and then from memory to the gigabit card).
Bus mastering only means that the CPU doesn't need to be involved when copying from one memory address to another. Converting from sectors read from the disk controller to the ethernet would still need a lot of packet processing, buffering for network protocol, etc that it is going to be some copying.
RAM is so much faster than IO that sometimes copying twice (buffering) is faster than letting the disk or network to wait.
OVERK1LL is right that gigabit would very likely saturate the PCI bus, but most newer chipset has the IDE/ATA/SATA/PATA controller internally and not on the PCI bus, and make it not limited by the PCI (SATA is 150MB/S or higher).
In theory, with busmastering, the disk controller should be able to talk directly to the gigabit controller so the data needn't be copied twice (from the disk controller to memory and then from memory to the gigabit card).
Bus mastering only means that the CPU doesn't need to be involved when copying from one memory address to another. Converting from sectors read from the disk controller to the ethernet would still need a lot of packet processing, buffering for network protocol, etc that it is going to be some copying.
RAM is so much faster than IO that sometimes copying twice (buffering) is faster than letting the disk or network to wait.
OVERK1LL is right that gigabit would very likely saturate the PCI bus, but most newer chipset has the IDE/ATA/SATA/PATA controller internally and not on the PCI bus, and make it not limited by the PCI (SATA is 150MB/S or higher).
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Originally Posted By: PandaBear
absolutely get the jumbo frame on all the cards and switches. gigabit is useless (or near useless) without jumbo frame.
Well, the 3Com doesn't support jumbo frames, and I won't be replacing it anytime soon. But apart from that, I was more curious about the large transfer speed difference one way vs. the other way.
absolutely get the jumbo frame on all the cards and switches. gigabit is useless (or near useless) without jumbo frame.
Well, the 3Com doesn't support jumbo frames, and I won't be replacing it anytime soon. But apart from that, I was more curious about the large transfer speed difference one way vs. the other way.
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I just replaced my little 8-port Cisco (cheap one) Gigabit switch on my desk with a Catalyst 2960-24-TT. 24x10/100 ports and 2x1000 ports. Got a wicked deal on it, and couldn't turn it down. Moved the 8-port down to the basement for my bench.
I just upgraded my network to gigabit not too long ago. Im using two DLink 8 ports. I just tested transferring a 6.5GB file across both to the next fastest machine. After the inital burst of 120MB/s it dropped quick to 100MB/s then slowly drifted down and stabilized at 90MB/s or about 750mbit. Pretty good, I think. 9KB Jumbo Packets.
I have 2 Trendnet GreenNet GBit switches that work great. I have a 5 and an 8 port. They have a metal chassis with rubber feet so they have a little mass to keep them from sliding off the back of my shelf with all the wires connected. They don't feel as cheaply made as most consumer switches. They also draw very little power if you care about that. They can be found for $24.99 on sale and usually have a $10 rebate to bring the price down more.
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