[ThatGuy]

Hi all. I have two dual ethernet motherboard based systems. All Ethernet interfaces on both motherboards are gigabit. For VNC purposes I decided to connect two of the systems directly with some cabling. Gb port to Gb port. Both systems detected each other's presence immediately upon connecting the cable (auto-sensing I guess) and both systems show "1.0Gbps" connection. Yet, when I transfer files the maximum I can reach is about 11-12MB per sec, which is really 100mbps limit. Both the of the Gigabit chipsets are identical (Marvell Yukon), and I even got identical driver versions on both systems. Both systems are pretty modern, with fast HD drives, plenty of RAM, and fast CPUs. (Which is not the issue, obviously, since the transfer speeds are hitting the 100mbps limit easily)

Anyone any idea?

[tain]

What kind of cables are you using?

[ThatGuy]

Cat5e, patch (30m). Tried Cat5e crossover, but it was a short cable (2m) and it worked just as well as patch which I needed because of its length. With patch it auto-negotiates to 1Gbps, but it runs @ 100Mbps, same with crossover.

[jcarle]

Perhaps you could try using a Category 6 cross-over. What about drivers? Are they up to date?

[tain]

jcarle, on May 9 2007, 08:34 PM, said:

Perhaps you could try using a Category 6 cross-over. What about drivers? Are they up to date?

The cables should be fine as 1000BASE-T is designed to work with Cat5 (5e and 6 are even better, granted). Are the cables homemade? Sometimes faulty RJ-45 jack installs can result in poor performance.

jcarle mentioned drivers; which do you use? Try http://www.marvell.c...ivers/search.do

[ThatGuy]

Hi. Cables are not home-made. Right now, I'm using the latest drivers. I also tried the drivers that came on the driver CDs for each motherboard, as well as some really old beta drivers that somebody recommended on another forum. Results were the same with all driver versions. Transfer speeds stuck @ 100mbps. (albeit, it's maxing out the 100mbps link at least) I mean if it's capable of running @ 11-12MB/s, surely it's capable of running 13, 14, or 15MB/s or much higher, which would indicate 1Gbps link... argh, this is frustrating. Everything looks A-OK except the fact that it is NOT A-OK.

[jcarle]

Something just nags at me that the cable could be responsible. The other thing to check also is to make sure that your network cards are set to auto-negociate or set them to 1000 only.

[ThatGuy]

Hmm, they are currently set to auto-negotiate. (Both are showing "1.0Gbps" link), but there is no way to force 1000mbps anywhere in settings, just 10 or 100.

[tain]

In Device Manager, on the Advanced tab for your adapter, there should be a setting you can set. Mine is "Speed/duplex settings" but YMMV.

[CptMurphy]

Check it out, it may not be the same thing, but I found this site that states that if you ever had trouble getting a gigabit connection with a crossover cable, it may be the pinout. Here's the site: http://logout.sh/com...rs/net/gigabit/


FYI, the pinouts do look different.

Also, from what I've been reading, you shouldn't expect to see anything past 25MB/s transfer speed unless you have a RAID array set up.

This post has been edited by CptMurphy: 10 May 2007 - 06:03 PM

[ThatGuy]

TAin, I checked, for me it's called "Speed & Duplex". There are only options to force 100mbps or 10mbps. (1000mbps is not even mentioned in any of the selections) Currently it is set to "Auto-Sense". I also enabled jumbo frames on both systems, but it had no effect on performance.

CptMurphy, I'm using a patch cable, like I mentioned above. 25MB/sec would be great if you ask me. (That would be exactly twice the throughput rate I'm getting now) Also, my systems are pretty modern. I even got a SATA-II RAID0 set up on one of the machines in question.

I'm really clueless as to what is causing this. I "googled" a bit today, but couldn't find out anything useful.

[cluberti]

Have you tried attaching the boxes to a Gb switch yet? I've seen some Gb ethernet cards on Nvidia-based motherboards with the Marvell Yukon chipset that just wouldn't negotiate at anything above 100Mbps with a crossover cable (even when pinned-out correctly). Attach them to a switch via straight-though CAT5e, and viola, 1Gbps. between the same two machines.

Marvell NICs are nothing but trouble, in my experience, and they're on that motherboard for a reason (and it isn't because they were the best - they're the cheapest MAC bulk money can usually buy that can be customized).

[ThatGuy]

Buying a 1Gbps capable switch at this juncture would not be "cost effective". I bought several routers and wireless access points in the last few months, so my "networking budget" is tapped out. Right now, I'm thinking it might be an OS related issue. I might try and boot both systems via some "live" version of Linux and see what happens with the link, but then again, that sounds too complicated and I'm not too knowledgeable when it comes to Linux.

This post has been edited by ThatGuy: 11 May 2007 - 02:17 PM