A7N8X Memory Problem

  MarvintheAndroid 22:38 16 Jul 2008

Hi. I have an ASUS A7N8X (standard) motherboard version 1.04 running BIOS v1008. Windows XP SP3. I recently upgraded from AthlonXP 2500 (Barton 333) to AthlonXP 3000 (Barton 400). No problem there.

However I have also tried to upgrade the RAM from DDR333 to DDR400, first buying 2 new 512MB modules from USA. These didn't work well, so I got 2 new 512MB sticks from Crucial, matched to the motherboard. Same problem.

In Windows, 3D games freeze (even simple ones like Quake 3) and lock the system COMPLETELY - cannot even CTRL ALT DEL. Before, the games ran smoothly. And the display keeps flicking to black for a second or so, then back to normal, several times a minute when in desktop, browsing internet etc.

If I insert one of my old 333 memory sticks along side the new RAM, forcing them all to run at 333 instead of 400, the problem goes away. In fact that is how I am using the system now and it seems perfectly stable.

I have run Memtest on the RAM and it detected no errors after an hour of testing.

My power supply is a 350 Watt Enermax job (EG365AX-VE) which up to now has been ample, would changing from 333 to 400 memory speed draw much more power ?

Could it be some sort of memory timing problem, perhaps others running this mobo at 400 DDR could post their memory timings ? Mine are 8-3-3-3T when running at 400.

Graphics card is a Galaxy Gf6600GT AGPX8 with a Zalman cooler. Never any problems before. CPU runs at 40 idle 48 load.

I cannot flash the BIOS as I don't have a floppy drive, but it is only one version behind the latest (2 months difference) and the update was to fix 3D Labs AGP cards and run Semprons. So I guess it should be OK.

Any other ideas what could be causing this odd behaviour when running the memory at 400 ?


  Ditch999 23:09 16 Jul 2008

You probably need to go in to the bios and set the ram to run at 400 mhz and you might also have to set the timings manually.
The timing settings you are looking for are named CAS, tRCD (RAS to CAS Delay), tRPD (Row Precharge Time), tRAS (Min RAS Active Time) and should have numbers beside them. Set CAS to 3, tRCD to 4, tRPD to 4 and tRAS to 8.
These will be safe settings. If you know your memory timings, something like 2.5-3-3-7 you can set them as that. Just remember that you have to set them to the slowest stick ie the highest numbers.

  MarvintheAndroid 21:16 17 Jul 2008

I have clocked FSB and memory down to 380 and it is now stable. I'd still like to know if there is anything else I can do, anyone out there running PCB version 1.04 at DDR400 ?


  MarvintheAndroid 22:27 19 Jul 2008

I'm putting this one down to a dodgy motherboard design. Still stable at 380 Mhz and SiSoft Sandra shows the difference in performance to be negligible. That will do until I get a new mobo.


This thread is now locked and can not be replied to.

Elsewhere on IDG sites

Xiaomi Mi Mix 2 review

What went wrong at the Designs of the Year 2017

iPhone X news: Release date, price, new features & specs

Comment utiliser Live Photos ?