Looking for advice with overclocking Opty 170

[Laztlain]

Hi All,

I have come accross a bit of a strange situation (to me at least!) while overclocking my rig. First, let me give quick system specs:

CPU: Opteron 170 (Sorry, I never wrote down the stepping and I can't take off my HSF to look at stepping cause I'm outta thermal paste!)
CPU Cooler: Arctic Cooler Pro
Mobo: Asus A8R32-MVP Deluxe
Ram: 2GB Kingston HyperX PC3200 (DDR400) 4x512MB sticks

I use the BIOS to overclock, and only use 3rd party programs for monitoring. Anyway, here are my current settings in the BIOS:

FSB - 265
Multiplier - 10x
CPU Voltage - 1.45V
RAM Voltage - 2.80V
RAM Divider - 166/200 (DDR440)
RAM Timings - 3-4-4-8 2T

Now if I bump the FSB at all, the system will not POST. So I reduced the RAM divider even more to 133/200 (DDR353) - this is below the normal RAM frequency.. still no post. Now here is the strange part... just to see what would happen I reduced the divider even further to a ridiculous 100/200 (DDR265)... and the system POSTS! At the previous 2 divider settings BOTH were below the normal operating frequency of the RAM.... any idea why one would post and one would not? Any advice on getting a higher overclock - I wanted to get to the 2.8 range.

Thanks!!!

 

[Martimus]

Did you lower your HTT multiplier to 4X? If not, than that is probably your problem. (even dropping it to 3X may help if you are trying to push it to 2.8GHz.)

Also, what does CPU-Z say your RAM multiplier is? AMD processors use a CPU frequency divider to calculate RAM speed, not a FSB divider, so you may be using the wrong equation to figure out what your RAM is running at.

edit: You will probably get a better performance boost by setting your RAM to 1T timings than increasing the frequency by 200MHz. AMD processors really take advantage of faster RAM, and that 2T timing kills performance on them.

 

[Laztlain]

Yeah I have the HTT multiplier at 4x, and also tried 3x at one point. I know that the A8R32-MVP mobo is kinda known for being able to run high HT speeds, and in fact I was stable up to around 1400 at one point (using 5x).

CPU-Z shows RAM multiplier as "CPU/12" when I have the BIOS set to 166 (shows a speed of 220) and shows it as "CPU/15" when I lower the divider to 133 (shows a speed of 176).

And I havent had much success with the 1T timing. From what I have read, using all 4 DIMM slots virtually means you have to set the timing to 2T. Is this true?

 

[MarcVenice]

Hehe I've got a similar problem, with a x2 3800+ which now runs at 2.6ghz, and ram is at 370mhz or so I think, instead of 400mhz. I used to run a FSB of 275 with a 3000+ venice, so I know the mobo can do it. The problem lies with nforce 4 chipset I think, which does NOT take kindly to running 4x512mb. And yeah, that also means you have to run with 2t instead of 1t. Sucks, especially since K8 really benefits from higher memory speeds.

 

[Laztlain]

Hi MarcVenice,
Is your mobo the nforce4 chipset? I believe my Asus uses the RD580 chipset, but I am assuming both do not take kindly to all 4 DIMM's being used and trying to run a timing of 1T.

 

[MarcVenice]

I've got a a8n5x, with a nforce 4 chipset. For some reason I assumed you also had a nforce 4 chipset, but I was wrong in doing so. Here's a AT review on your board: http://www.anandtech.com/mb/showdoc.aspx?i=2697 Maybe it helps ?

 

[Bwd4]

Try to keep your HTT around 1000, dropping it down to 3x wont hurt, and will help stability, atleast it did when i ran a 170. Also run your Ram as close to 200mhz(400ddr) as you can as the IMC on amds chip dosent make use of the extra bandwidth, do try to keep the speed around 200mhz with low timings.

I used to run a DFI Ultra-d, and my chip had problems going below a 5/6 divider, whenever i did it wouldnt boot windows, so some chips/mobos just agree with eachother. my advice is to drop your CPU multi and test out which ram dividers work and which ones dont so you know its your ram making you not post/boot.

 

[Laztlain]

Marc - I have seen that review before... in fact, that review was the main reason I bought this board! AT did a nice follow up article on the board when the new 0404 bios was released that specifically covered overcloking - all good info.

bwd4 - I have my HTT set at 4x right now for a speed of 1060 using a FSB of 265. I will try your suggestion on dropping the CPU multi and testing different dividers when I get home tonight.

 

[lopri]

Thought A8R32-SLI is an ATI chipset board?

Anyhow, usually on NF4 the first things you need to loosen as you raise the HTT are Max Async Latency and Read Preamable. Can you find an A64Tweaker or a similar app and post a screenshot?

 

[Bwd4]

that and also play around with HTT voltage, once you start clocking it up you might need to give it a .1v-.2v bump to get it stable. my 170 maxed out around 2.9ghz with 1.475v, 2.85ghz with 1.425, so thats where i kept it.

What kind of temps are you getting with 1.425 on that cooler? i know my arctic freezer 64 temps were hitting mid 60's with 1.425 and about 55-56 on a coolermaster geminii.

 

[Laztlain]

The board I have is an ATI chipset board - it uses the ATI RD580 chipset (the board is the A8R32-MVP Crossfire board, not the NF4 SLI board).

I will post a screenie when I get home tonight.

bwd4 - the temps I was getting were a little lower, but I have my case open right now. Also, do you have 4 sticks of RAM in your machine? I would love to hit 2.9ghz but I am starting to believe having 4 sticks of ram is holding me back....

 

[Laztlain]

Okay - here is a screenshot showing memory timings and current settings:

SCREEN

basically that FSB of 265 is my max unless I turn the RAM divider WAAAAY down... any suggestions are welcome!

 

[heyheybooboo]

Originally posted by: Laztlain
Okay - here is a screenshot showing memory timings and current settings:

SCREEN

basically that FSB of 265 is my max unless I turn the RAM divider WAAAAY down... any suggestions are welcome!

You need to drop your HT to 3X and keep it below 1000MHz. This will not impact your overall performance.

You need to drop your ram divider from 166mhz to 133mhz. You are running your ram more than 10% beyond spec. (AMD ram is 'double-pumped' - when your ram freq says 220.7 it is running 441.4mhz)

With your HT @ 3x and your ram divider at 133mhz you have the headroom to approach a cpu fsb speed 300mhz ... and beyond with good kharma

If you go above 300mhz cpu fsb you will need to drop your ram divider again to stay in spec ....

 

[Laztlain]

Hi, I tried lowering the HT to 3x, for some reason that setting does not agree with my setup. My mobo has a feature where if you overclock it to the point where it will not post, you simply power down, restart, and the BIOS gives a statement like "Overclock Failed!" and you can change the settings again. But with the HT set to 3x, even this recovery feature does not work and I need to clear the CMOS every time. I have used different settings in the past where the HT was 5x and the FSB was around 250 with no issues (this mobo does very well with high HT settings).

In order to find the different limits of my setup, I set the RAM divider as low as it could go and set the CPU multiplier to something like 4x and was able to push the FSB to about 310 before seeing any issues. So then I started to raise the CPU multi but the system would not post at 8x or higher (even with pumping an extra 0.2v to the CPU). This was somewhat suprising to me becuase at 8x by 310 FSB the CPU would only be at 2480 mhz, but I can run stable at 2600+ mhz using a lower FSB and higher multi.

I also was using lower dividers for the RAM but again was getting issues with a FSB above 265... I guess this points to the CPU as the limiting factor then?