Gigabit optimization help

G

Gio

Weaksauce
Joined
Nov 25, 2005
Messages
68
Network setup:

Main PC in sig
DIR-655
Custom WHS running a Intel Pro 1000 GT nic (Pentium D930, 2gb ram, WD 640 black, 1.5TB Seagate)

Both systems are setup to use jumbo frames, 9000 on the main pc and 9014 on the server (Intel setting). Turned off flow control on both which seemed to help. Maximum transfer speed I get between the 2 is 60MB's/sec when transferring files. Which is good don't get me wrong but im trying to find what else I could do to increase the speed closer to 100MB/s. I've tried reading up as much as I could and the only things I could come up with are:

CAT 6 cabling (which I cant see making an impact over my CAT5E with 3ft runs)
Atheros onboard nic
WHS operating system itself

Aside from enabling jumbo frames and turning off flow control I haven't made any Driver or OS changes. Any help to increase my speed would be greatly appreciated.

Thanks :)
 
what kind of switch are you using?

cat5e vs cat6 won't matter at home on a short run...

crummy ethernet cards are often to blame... for example the built in "gigabit" ethernet adapter on my Dell laptop never gets more than 40-50MB/s
 
If you are measuring using file transfers, don't forget that your network cannot transfer more than you disk can read or write...you normally won't see more that 60-70MB/s net to/from a single spindle desktop drive. If you are consistently seeing 60MB/s and you don't have especially high performance disks on each end then that may actually be pretty good.

If you want to test the network performance, do what you can to eliminate the other performance limits during the test. File transfer speed tests are good, but set up a large RAM-disk on both ends to source and sink the test. That way you will know that it is the network performance you are testing and not the limits of your disk performance.
 
For a switch im just using the DIR-655's built in ports since the router is gigabit. The main PC has a velociraptor which is over 100 MB/s avg and the WHS has a 640 WD Black and a 1.5TB Seagate both which average over 100 MB/s for speeds. I replaced the OS drive and the hardware in the WHS and the speeds are the same so I don't think its a hard disk issue. I can try setting up a ramdrive to test and i will try out jperf. As for the onboard gigabit nic i have no problems replacing it if its the problem, but id rather not spend $50 on a Intel nic not being the issue when I can pick up a new prosafe switch for the same price. Basically if its a software config problem I am not that versed in networking to pin point the problem but if its a hardware bottleneck i will gladly replace the issue.
 
I don't know if this makes you feel better or not but I have a DIR-655 router as well and I have never seen transfer speeds above 60-65MB/s.
 
mmmmmdonuts said:
I don't know if this makes you feel better or not but I have a DIR-655 router as well and I have never seen transfer speeds above 60-65MB/s.
Click to expand...

Sorry but it shouldn't. I have a DIR-655 and have seen over 80 MB/s. You really need to use iperf to do a proper speed test, then find the bottleneck, be it hard drives or NICs.

Edit: and that was without jumbo frames.
 
from what I've read the 655 supports 4k jumbo frames on WAN and 9k on LAN. Could very well be the issue though
 
I had a DIR 655, and got a constant >90MB/s between machines with 7200rpm drives.

My "oldest" machine is a I7, so everything from disk controllers to network cards are on PCI-E. All intel nic's except for my desktop machine, which is Marvell.

From what I have seen, bottlenecks for GB transfers are disk, disk controller, and nic/driver.
 
From D-Links knowledge base -

Why can´t I use jumbo frames of 9600k or above?

The Switch processor of the DIR-655 does not support jumbo frames above 4000k.
 
Like adi said, intel gig nics,i7 as destination, hitachi 2tb in source(old sever), dir-655 in the middle.

I dont use this setup anymore though, now use a lower power board for the server and am limited to PCI NICs which gives me only 55MB/s
 
This is where my knowledge might not be up to par. The onboard Atheros is PCI-E based which could very well be the issue. The Intel pro 1000 GT is a PCI card but unless I'm wrong the PCI bandwidth should be 125MB/s. As for the DIR-655 I've heard so many mixed things about the jumbo frames and it being resolved in a past firmware to support 9k frames on the LAN ports. People including adi have been able to transfer close to 100MB/s so I don't know if the bottleneck is the router. As for the disk controllers, if they are both Intel Sata II based and the drives themselves don't go below 80MB/s speeds could that be an issue?
 
Gio said:
This is where my knowledge might not be up to par. The onboard Atheros is PCI-E based which could very well be the issue. The Intel pro 1000 GT is a PCI card but unless I'm wrong the PCI bandwidth should be 125MB/s. As for the DIR-655 I've heard so many mixed things about the jumbo frames and it being resolved in a past firmware to support 9k frames on the LAN ports. People including adi have been able to transfer close to 100MB/s so I don't know if the bottleneck is the router. As for the disk controllers, if they are both Intel Sata II based and the drives themselves don't go below 80MB/s speeds could that be an issue?
Click to expand...

Just keep in mind that PCI is 133MB/s SHARED bandwidth. Like in my case, my sata controller and NIC are both PCI giving me a theoretical maximum of 66.5MB/s when transferring over the lan. I end up with about 55MB/s.
 
Ah that makes sense! Would the ICH7 controller be PCI or PCI-E based? The only thing is that the unit was previously a socket 478 P4 and the speed was the same. Upgraded the WHS and the only PCI card on the WHS is the nic but I do have an onboard Atheros PCI-E gigabit nic on that system as well I could enable if that is the case. The main PC and the router havent changed otherwise.
 
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I believe the ICH7 controlls the PCI and PCIe lanes but i could be wrong. I'd just do a little trial and error with the NICS. Also use iperf to eliminate disks as the bottleneck.
 
So I found my bottleneck. My Intel Pro 1000 GT PCI card !! With my once again rebuilt WHS, the new onboard Atheros GB nic transfers 85MB/s steady among both PC's.
 
That's 100% it. The card is literally a few months old off the shelf. No other PCI cards and the card was moved to a new build and the speeds remained the same. Awesome card but slow bus effected my speeds. I hope this helps anyone else with similar issues or doubts of the DIR-655's performance. I'm thinking I'm at my hard drives limits now which I am satisfied with. I will replace the one cable to the server with a CAT6 tomorrow (only a cable bucks for me) and report if there is another change again. Ty to all that helped :D
 
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