A8N-SLI Stability Probs

[pol II]

Hi; currently, my computer consists of the following:

ASUS A8N-SLI (bios 1008)
FX-53 stock 2.4xx GHz (12 x 201) @ 1.5v
1 x 512 Ballistix PC4000 @ 22-2-2-7-1T@2.8v
2x GeForce 6800 Ultra
74GB Raptor on Sata 4
Lite-On DVD-ROM
Enermax 600w Noisetaker rev 2.0

At the above settings, the system is completely stable. I have 2 problems however that I was hoping to get advice on:

My first problem goes like this: when I raise HTT speed above about 210, the system becomes unstable. Windows take longer to appear and I cannot finish the first graphics test in 3D Mark 03. The computer will completely shut down requiring a hard reboot about mid-way through the first test. My goal is to keep CPU speed constant at 2.4GHz but use the settings: 10 x 240.

In preparation for raising HTT to 240, I did the following:

1. Set Hypertransport to 3x or 4x (tried both)
2. Lock PCI and PCIe @ 33.33 and 100, respectively
3. Set CPU multi to 10
4. Set CPU "bus" to 240
5. Adjust RAM timings to PC4000 SPD (2.5-4-4-8-1T)

I will get crashes and instability whether I change the parameters in BIOS or in clockgen. Setting RAM to 333MHz will get me to 2.4GHz without problem, but my goal is not to run the divider; rather, I want to increase the memory speed. I did not have this problem on my ASUS A8V (CPU, RAM, HDD are the same on this mobo).

So the timings are relaxed, vdimm and vcore are set appropriately.

RAM module passes memtest86 without error (at tight or relaxed timings)

My second problem revolves around DDR DIMM A1 (the first slot if looking at the slots from left to right and used for dual channel when DIMM B1 is occupied). I have two sticks of Ballistix 512. Each passes memtest with flying colors if in slot B1. However, if both B1 and A1 are occupied contemporaneously, with any combo of RAM modules, it begins to fail memtest. This signifies a problem with the memory slot A1. What should be my next step?

Thank you in advance for any input.

 

[GuitarDaddy]

I have the same board. The PCI and PCI-E settings in bios don't work. If you boot to windows at stock speed then overclock your PCI and PCI-E aren't locked!!!!

To activate the locks on this board set HTT to 201 or higher in the JumperFree section of bios. Then when you boot up and overclock in windows the buses will be locked. You can see this for yourself by downloading "Clockgen NF4" its a windows app that shows your PCI and PCI-E bus speeds. Check it out, boot up at stock and overclock it a little bit and watch the buses go up. Then reboot and set HTT to 201 and they will stay at 100 and 33.33

I can almost 100% gaurantee this is your problem.


And I think you must have an FX-55 because and FX-53 is a socket 940 chip and wouldn't work on this board. Very nice rig

 

[pol II]

Hi Guitar Daddy and thanks for your comments. It turns out that the HTT is indeed set to 201 in the Jumper Free section of the BIOS (I hid that little tidbit in the description of my system, sorry). I had done several forum searches and your advice to do this came up in several threads - so I did it, and it does lock those busses. I apologize for not making it more clear. As for the processor, I wish it was an FX-55! It is definitely a socket 939 FX-53 though; they did make a 940 version as well. Maybe it was the FX-51 that was 940 only?

So, unfortunately, I have done as you suggested and have the problem nonetheless. Any other ideas? 'Cause I'm stumped.

 

[MADMAX23]

Using the DDR333 divider has no negative effect on memory performance/bandwidth, I tested it.
Your memory should run at 240 Mhzs at 2.5-3-3-7 1T timings.
You could try another Bios version. 1006 is the best for me right now.
I am running my HTT at 289 Mhz rock-solid using the DDR333 divider. 289x9= 2600 Mhz

 

[GuitarDaddy]

You may just be hitting the 1T wall on this board. Depending on which bios's I've used, for me the wall has been between 238mhz and 245mhz. Everybody talks about the 250mhz 1T problem on this board, but for me the wall has always been lower than that.

And in my testing 225-235mhz 1T beats anything that I can run 2T up to 290mhz. So my advice would be to Adjust multi and mem divider to run your ram in the 220-235mhz range.

268mhz x 9 = 2412mhz with the DDR333 6:5 divider this would give you roughly 223mhz ram

Or you could most likely get
289mhz x 9 = 2601mhz with the DDR333 6:5 divider with ram at 236mhz. These are the settings I ran with my 3200+ winchester on this board.

I'm currently running
280mhz x 10 = 2800mhz DDR333 ram=233mhz with a San Diego 3700+. If that FX is a good overclocker you might get these settings. You would need better than stock cooler though.

And thanks for the info on the FX-53! I wasn't aware they made a 939 version. I thought it was like the FX-51. Is that a Clawhammer, Hammer or Sledgehammer? Very nice chip!

 

[pol II]

My original intention was to test the effects of increased memory bandwidth vs stock...at the same CPU speed. The easiest thing to do, of course, is to lower multi and increase HTT, but that won't work. Perhaps I am hitting a wall at 1T command rate. Even with HTT set to 218, system remains unstable, so maybe the wall is a lot lower for this board. I'll try running some dividers, as it seems to be the only way to do this, unfortunately.

Anyone have an idea of what I should do about the RAM slot problem? I am thinking of calling ASUS soon. Thanks for the help guys, and looking forward to advice on what to do about the DIMM slot (never had this happen before).

Edit: my chip is a ClawHammer. It is not the greatest overclocker in the world to say the least It will run 2.6GHz @ 1.525 prime-stable forever, but getting above 2.7 will not happen with anything less than *cough* 1.8v. I have the CPU watercooled, so I gave it a shot on my ASUS A8V a few months back. Oh well, I am at least glad that it will get to 2.6 at a thermally-reasonable voltage, so that's cool.