Gigabit LAN Issues

[Sanosuke]

Hi Folks,

I wouldn't post but I've scoured forums and the net looking for a solution to my LAN problems with no success.

Networks Specs
-LinkSys WRT310N router
-Marvell Yukon onboard gigabit NIC
-DNS-323 NAS attached
-Running Windows XP SP3

Both my computer and the NAS are connected to the WRT310 by Cat5e cabling. When I copy files between the two locations I get speeds from the NAS of around 40-90 Mbps (thats megabits folks!!). I've been trying to determine why I'm getting such abysmal rates, but haven't had any luck. I understand the DNS-323 is supposed to average around 15 MBps(bytes), but I'm getting nowhere near that.

I've tied adjusting my TCP window size, MTU, disabled (and uninstalled) QoS, have ensured that everything is connecting at 1 Gbps, any advice would be much appreciated as I'm ready to pull out my hair at this point.

Thanks,
Sano

[thiggins]

Is the problem only between your computer and the DNS-323 or do you get low speed with transfers to another computer with a gigabit NIC?

[Sanosuke]

I can't test transfers between my computer and another with a gigabit nic as I don't have any other computers in the house. I could test it with a laptop with a 10/100 card, but I'm not sure how helpful that would be.

[thiggins]

In checking the NAS Charts I think you may not actually have a problem.
The attached NAS Chart plot shows performance between 10 and 15 MB/s in the larger file sizes, using iozone. So it's possible that you are seeing the speeds that you are reporting.

To know for sure, I think you need to get a run with another gigabit machine.

Are read and write speeds the same? How is the NAS configured, RAID 0, 1, JBOD?

[Sanosuke]

I'd agree with the speeds being close, although they fluctuate between 4 MB/s and 9 MB/s with large files in my situation, never attaining anything close to a steady 10-15 MB/s. It may seem trivial, but the difference between an average of 7 MB/s and anywhere between 10-15 would help out a lot with large file transfers.

I've managed to test the gigabit connection using a friends laptop, and between 2 xp machines (my desktop and the laptop) through the WRT310N I was getting significantly faster speeds, around 30-35 MB/s copying from the laptop. Does this mean I should just write off my 5-10 MB/s speeds from the DNS-323 as average? or is there something going on that could be causing my speeds to 30%-50% of their potential?

My NAS is configured as a standard config, no RAID, or JBOD.

Thanks for you assistance,
Sano

[thiggins]

Windows to Windows transfers can take advantage of file transfer optimizations built into the OS.

Looks like there is no particular problem with the DNS-323.

[Sanosuke]

So I can expect to get nothing higher than 8-10MB/s? That seems rather disappointing given that I've seen higher benchmarks and reports of people with speeds twice this. I suppose it's livable though, if nothing can be done.

Thanks for the help,
Sano