Help me get more from my X2 3800

Soldato
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14 Mar 2004
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Brit in the USA
I can only get my X2 3800 up to 2.2GHz - any higher and it fails Prime almost immediately. I've tried raising the vcore, the RAM voltage, running the RAM at 667 instead of 800, loosened the timings, changed the HT speed to 4x.....temps look OK. I'm not sure what else to try. I thought it would be better when I dumped my old Biostar board for a Gigabyte (I didn't swap purely for OCing reasons...) but still no joy. Have I just got a lousy clocker?
 
Sorry, I'm not to sharp when it comes to OCing CPU's :)

If I lower the multi then surely I'll have to increase the FSB speed to compensate? I can't raise the multi, so increasing the FSB is the only way to go.
 
I'm just saying if you drop the multi and still can't increase the FSB any more than you have reached the FSB limitation of one or more of your components.

Are you setting memory timings manually or on auto? You may need to relax your memory timings. Try 2T instead of 1T

You don't mention what spec you have, so all sorts of things can cause this, it could be you have 4 SIMM slots full, try it with 2, did you lock the PCi bus at 100Mhz?

Show us a screeny of CPUz, processor info screen and RAM info screen and lets go from there. Also Coretemp or Speedfan if you can so we can see some temps.
 
Mines is nice at 2.81, goes further, but gets a tad hot :P

Must be lots of potential left in yours!

Change the multiplyer to 4x
Lock anything you can, pcie, etc
set the ram up nice, manually, unlinked to the fsb of the cpu
then just up the fsb of the cpu :)

if you get places and feel there is more left, put the vcore of the cpu up very slightly, i think i put mines up to 1.4v :)
 
If you get to a dead end and nothing else helps, try setting the pci-e freq to 99 or 101 on the offchance - have heard that this can sometimes be an issue.
 
Bah, I give up. I've tried everything you guys have suggested and nothing works :( Most of the time it won't even POST, yet alone make it into Windows for testing. Just for the record, here are the complete specs...

GIGABYTE GA-M57SLI-S4 Socket AM2 NVIDIA nForce 570 SLI AMD Mobo
AMD X2 3800 CPU (the original, not the low energy version)
Stock heatsink/fan + AS ceramique
2GB g.Skill DDRII800 5-5-5-15
XFX GeForce 7900GS 600M PCI-E
X-FI Xreme music
X-Clio 460W stablepower PSU
Seagate 80GB IDE hard drive
WinXP SP2

Thanks for all the help btw :)
 
You've just reached a FSB wall of either the CPU, the chipset or the memory. Not much you can do apart from replacing parts.
 
I had a gigabyte board with my 144 opteron 939 socket, think it was a K8N or something, anyway, would sometimes post at 220 then once it got hot it would only post at 210.
I dropped my HTT to 2x then it went over 280 fsb.

The posting issue was down to the passive heatsink under the GFX card getting very hot then refusing to post until -210 fsb.
I put a fan in the side of my case blowing on the sink and had no more probs.

Don't know if this will help.
 
Check the BIOS for spread spectrum settings and disable them all. I've a MSI 570 Ultra board and it's really bad at overclocking but to get it higher than 230 or so I needed to disable the spread spectrum settings as that was the only way to lock the PCI bus.

Also the MSI 570 Ultra board is terrible at overclocking because of a design fault and possibly the same problem exists on other manufacturer reference boards. It's something to do with the power regulation or something like that and means I can't even up the vcore past around 1.35v before it starts to sometimes not boot properly and then loses the CMOS settings.
 
Curio said:
I can only get my X2 3800 up to 2.2GHz - any higher and it fails Prime almost immediately. I've tried raising the vcore, the RAM voltage, running the RAM at 667 instead of 800, loosened the timings, changed the HT speed to 4x.....temps look OK. I'm not sure what else to try. I thought it would be better when I dumped my old Biostar board for a Gigabyte (I didn't swap purely for OCing reasons...) but still no joy. Have I just got a lousy clocker?
I just had a similar issue with my X2 3800, which I could only get to 2.1GHz!

I knew that wasn't right, so I went looking.

It turned out that the problem was having the CAS for the memory set to 'Auto' in the BIOS. I had just set the divider manually (I was looking for 250x10, so I wanted a 5/6 divider, as you have, which would set the memory to a small overclock) and left the rest at auto.

When I manually set it to 3, which my standard Crucial PC3200 is rated at, the problem went away. I currently have the CPU at 2.6 and the memory at ~216, with an S&M full load CPU and memory test passed. I'll probably leave it at that - CPU temps went to 54/61 at 2.6 and that's hot enough for me.

If you have better RAM than I do, you may be having the same problem at a slightly higher speed.
 
Curio has a socket AM2 setup not socket 939. He should be able to leave memory settings at the defaults and the board will pickup the highest speed rated SPD settings even when using a divider.

Curio, have you tried using a 533 or 400 divider?
 
Curio said:
I can only get my X2 3800 up to 2.2GHz - any higher and it fails Prime almost immediately. I've tried raising the vcore, the RAM voltage, running the RAM at 667 instead of 800, loosened the timings, changed the HT speed to 4x.....temps look OK. I'm not sure what else to try. I thought it would be better when I dumped my old Biostar board for a Gigabyte (I didn't swap purely for OCing reasons...) but still no joy. Have I just got a lousy clocker?

do you really need to go further? Why not wait till the AMD quad cores come and replace - i assume you have an AM2 socket?
 
Could be the RAM being overclocked.

Should be an option in the BIOS to set the speed, either by a divider or it might just be in mhz. Make it slower if it isn't already.

I have an s939 mobo which doesn't list dividers, but just has '400mhz' '333mhz' and '266mhz' options, which represent three dividers themselves. I had to put it to 333 and then 266 to overclock my Athlon 64. Which runs stable at 276fsb :p
 
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