Gigabyte GA-8SQ800 damn low memory bandwidth.

[Anotherone]

I recently bought this mobo along with two sticks of TwinMOS PC400 DDRAM memory (each 256MB). In order to have dual-channel working I inserted them in the slots 1-3 (also tried 2-4). After reboot the POST screen says "DDRAM Clock: 400" and "DRAM dual channel: single 128 bit mode", which I guess means that memory was correctly recognized and should be working in dual-channel mode. Under WinXp when I run Sandra's memory bandwidth, benchmarks results are surprisingly low - only about 2550MB/s. I saw reviews of this board and other boards with SIS655 chipset and all had results above 3300MB/s. My BIOS version is F5, which is bit strange because currently latest BIOS for this mobo on the Gigabyte site is F4. When I remove one memory stick, dual-channel isn't working of course (POST screen says it's disabled), but test results are almost the same. I also tried to underclock memory frequency to 333MHz, without any bigger influence on the resulting bandwidth. It looks like dual-channel isn't working though BIOS says something different. Please help me I spend lots of money on this mobo and memory and it's in fact slower that my previous SIS645 mobo. Thank you in advance.

 

[LumberJack]

Personally i'm running the Granite bay version of that board with no such problems First about the bios. Typically the bios that comes with the board is one version newer than the web site.. that's typical for Gigabyte boards.
First try checking the web site to see if there are any new bios updates. Some quirks ussually arise with new boards.

First check the ram slots. One should be in channel A and one in B. It seems you have that correct. Next make sure the ram modules have the same specs exactly. Then if problem persists, try manually setting the ram timings in bios which would assure the modules remain the same. Check the Ram speed in bios. There are some issues with this board and PC400 RAM. Try running it at 333.

Hope something above works... Let me know what happens. And yeah you should be getting like 3330MB/s on the bandwidth mark.

To err is human... to really screw things up you need a computer!

 

[ntrop]

I got this board a couple weeks ago with two sticks of kingston hyper-x pc3000. The shipped BIOS version with mine was F3 and I updated to F4. I'm getting scores of around 3400 on Sandra's mem bandwidth which seemed strange to me because I get around the same score whether I'm running "single 128 bit mode" or the "dual 64 bit mode". The F5 Bios sounds kinda shady. Was the board sealed when you got it? Somebody could have flashed the wrong BIOS or something, I would save that one with the Gigabyte utility manager and try putting the F4 BIOS on it and see if that doesn't help. Good Luck.

 

[Anotherone]

I found where the problem was, kinda stupid from my side though. I have only P4 2.0GHz (should wrote this in my first post), so with FSB 100MHz I cannot get better scores. I tried to overclock to the max (FSB@131MHz and RAM@425Mhz) and my score went up to 3300+MB/s. And this is logical, with 100MHz FSB max. memory bandwidth is 4*100*8=3200Mbit/s. With 133MHz FSB it's 4*133*8=4200+Mbit/s. It looks like Sandra measures about 80% of max bandwidth in both cases.
I guess you both have CPU with FSB 133MHz, right?