Need help overclocking Athlon X2 4200

[JustJoinedToday]

To make a long story short, I just bought 2 x 1 gig sticks of memory to match with my X2 4200 processor. I currently have the processor overclocked to 2.8 Ghz. My problem is that Super PI, Memtest, etc fails unless I get the memory running at 200 Mhz.

The two sticks I had in before were 2 X 512 Mb sticks running with a 5:3 divider (255 FSB\215 memory) and everything was stable (Prime, Memtest, SuperPi, etc). To get the 2 gigs stable, I have to run 255 FSB\ 200 memory (a 3:2) divider. At this everything is stable, but the memory is rated for at stock a FSB of 250 (pc4000) so I would expect to at least keep the settings I had before. The volts on my memory is 2.7 and 1.45 for CPU.

If anyone has a similiar system, what am I doing wrong, or does the memory controller on the Athlon limit my overclock with 2 gigs of memory.

System Specs:
Athlon 64 X2 4200 Manchester Core (CPU-Z) ovrclkd @ 2.804 Ghz (255 x 11)
Corsair XMS PC400 (2 gigs) memory
Asus A8V Deluxe motherboard
ATI X800 Pro graphics card
300 gig Seagate hard drive (IDE)

 

[Zebo]

Two 1024's are harder to clock than two 512's - what timings?

 

[stevty2889]

Originally posted by: Zebo
Two 1024's are harder to clock than two 512's - what timings?

Yep, Zebo is right. I have to have my 2 1gig sticks at slightly under 200mhz to keep them stable. Have to remember that the memory controler is on the CPU itself, so when you are overclocking, it might not be able to handle the memory at it's rated speed. It's not really causing a major performance hit anyway. Thats a very nice OC by the way, my 4200+ is at 2.618ghz.

 

[imported_miahallen]

Welcome to AT!

The sticks may be rated at 250MHz, but they're rated at that speed certian timings. Did you make sure to double check what timings your set at now, the BIOS may have defaulted to timings faster than required for the PC4000 designation. Or try relaxing the timings even further, and you should also be able to push the voltage up a bit more (safely).

 

[Zebo]

Well we have anceint 4200's stevty - new ones make 2.6-3.0.

 

[5t3v0]

I had various issues moving up to 2Gb. The main one was that there were a lot of memory timings lingering around from my old sticks which I'd set explicitly which the new sticks didnt like. I cleared the CMOS to reset everything but I guess you could just load optimized defaults to see if that resets anything you might have set. I also found that my sticks performed better on lower volts than the Auto setting gave them but that's maybe a G.Skill specific preference. These G.Skills worked fine at 250MHz 3-4-4-8 1T but wouldnt OC to 275-280 to run 1:1 with the cpu, so I've used the 166 divider which results in underclocking the memory frequency to 229MHz. I have tightened up quite a few of the timings as a result though.

 

[stevty2889]

Originally posted by: Zebo
Well we have anceint 4200's stevty - new ones make 2.6-3.0.

True, I got mine when the 3800+ X2 was still a rumor. But darn glad I have it, it has given me no troubles. Other than my Dothan, all of my Intel chips have been nothing but trouble lately(overclocking wise that is), especialy the dead core on my first presler.

 

[JustJoinedToday]

Thanks for the responses guys. My memory timings are (from CPU-Z) 3.0 - 3- 3 - 7. The bios defaulted to this I guess because of the divider i'm using (3:2) which puts the memory at 200.3 Mhz.

I tried uping the voltage to 2.8, the max for A8V Deluxe, but the sticks, (or memory controller) seemed to become unstable. It errored out in SuperPI doing 32M during the first iteration. At 200 Mhz, its stable (ran memtest and Prime95 overninght and no errors or warnings when i got up this morning).

I tried setting the FSB to the limit of the memory controller (240 Mhz) and running a 1:1 divider. I was doing this with my 512 sticks, but found that i got better performance with 255*11(2.8 Ghz) than 240*11(2.64Ghz) even though I had to use the 5:4 memory divider (215 Mhz). With 2 gigs, Windows didn't even startup at those settings.

So where i stand is 2.8 Ghz processor and 200 Mhz memory. I guess that's not too bad.

 

[Bobthelost]

Not too bad...

So roughly the same performance as the soon to be released 5000X2 chip, yeah i could live with that.

 

[5t3v0]

Does the memory run stably at 3-3-3-7? Have you got the C2PT with the 2-3-3-6 timings or the PT with 3-3-3-8? I'm presuming the latter by the settings. If so, that's a small boost for free. I'm still surprised you cant run the memory at 215MHz as this is a pretty modest overclock even for 2Gb. Did you explicitly set the timings to SPD defaults before trying the 5:4 divider? You need to look at more than just these 4 timings as there's others seem to get reset when using a divider. What I did was set the mem & cpu 1:1 at 200MHz HTT and then go through the settings in the BIOS and explicitly set each one to the same as the auto setting. Then when I raised HTT & set the divider, the mem settings were locked at their 200MHz defaults rather than getting reset to 166MHz SPD or whatever the BIOS did. You can then relax any timings from here as required to get your desired overclock. In reality, the jump in mem frequency from 200MHz to 215MHz will have minimal impact on your performance and might not be worth the hassel & time it will take to set up. I wish I had a board with the 5:4 divider then I could get stock speed out of my PC4000. Next upgrade perhaps....

 

[TrevorRC]

Run the memory @ 3-4-4-8

 

[Tweakin]

That's a nice OC...wouldn't complain too much about that. When I went to 2x1GB sticks, I had to slack off on the memory timings to 3-4-3-8 to keep it stable, and I believe it is due to the memory controller in the chip. My Opty could push 2.95 with the 1GB OCZ, yet only 2.75 with the 2x1GB sticks on the same board. (Prime Stable for 12+ Hours)

I now have a serious wall @ 2.6 which I didn't have with my 2x512MB OCZ Plat Rev 2 TCCD sticks like you do, but I'll take the looser timings and loose 100+Mhz for the added memory any day.

edit: Forgot to add that to keep the memory stable at this speed and 1:1 timings along with a 1CR, I had to push the vdimm up to 2.72v.

 

[JustJoinedToday]

 

[JustJoinedToday]

The memory's stock timing is 3-4-4-8 at 250 Mhz. Since it appears that I am limited to 200Mhz, I played around with the timings and it appears I can run stably (Memtest for 2 hours) at 2.5-3-3-6. Testing this speed in Sandra, i'm getting pretty much the same performance that I had with my 2 512Mb sticks. I'll run Prime95 over night to make sure all is stable at these timings, but if so I can definitely live with the over clock that I got for 2 gigs of RAM.

It would be nice if someone did an official review (maybe someone has???) of just how dual core AMD's overclock with 2 gigs of memory.

If my experience is any indication, the memory controller will limit just how much the FSB can be raised depending on the amount of RAM you have. Anyone with the technical know how want to challenge that??

 

[Bad Dude]

I think all of the X2 4200+ are manchester instead of Toledo so the overclock won't be as high.