Stock CPU heatsink/fan to blame for 3DMark crashes?

[Drunkentig3r]

Recently I was able to overclock my AMD Athlon 64 3500+ (Venice-socket 939) from 2.2Ghz to 2.6Ghz. After fiddling around with .5 settings and learning that they weren't effective. I finally got around to setting the FSB to 260 and the multiplier to x10. Now, when I try to run 3DMark05, my computer crashes (my case fans and such continues to run, but my monitor turns black and I cant turn it on again for a bit). This happened both when I had it at 248x10.5 (my previous setting), and the new setting at 260x10. It crashes right around the 4th test or so, when the test shows a zeppelin flying overing a body of water, with a huge monster starting to attack it from under the sea (Right after this test finishes, it crashes). I was wondering: could it be because of the stock AMD heatsink I have running? It seems the CPU is being strained more then my video card, and I was thinking perhaps its because I don't have a third party heatsink/fan. I have no problems at all running the latest games, so its probably not the video card crashing I've heard how the stock HSF doesn't handle overclocks well since they are only tested for stock speeds, so I was just thinking this could perhaps be the reason. Any input will be appreciated thanks.

My rig specs:

AMD Athlon 64 3500+ @ 2.6Ghz (939)
MSI K8N Neo4 SLI Motherboard
Stock AMD Heatsink/fan w/Arctic Silver 5 Thermal Paste
MSI Geforce 7800GT w/Arctic Cooling NV Silencer (not OC'd yet)
OCZ 1GB (2x512MB) Value Series Dual Channel kit w/modified timings (stable)
2x120mm Antec Case fans
Western Digital 250GB 7200RPM ATA Hard Drive
Lite-On 8X Dual Format DVD Burner
Generic DVD Drive
Antec Smartpower 2.0 500W Power Supply
Antec Super LANboy ATX case
Onboard Creative Soundblaster! 24 Bit sound drive

 

[imported_Vanden]

What voltage are you at and what are the temps?

 

[Drunkentig3r]

CPU Vcore: 1.54 V
Memory Vcore: 2.70 V

Temperatures according to this core program I have are:

Idle CPU Temp: 37*C

Idle System Temp: 33*C

 

[imported_Vanden]

At 1.54 V you are probably pushing what the stock cooler can handle. I should have asked the load temps, i'm guessing about 50°C (try speedfan).

How stable is superpi 32M and prime95? If everything else is stable and you are happy with the oc, leave it as is. If you want to get higher or aren't stable a better cooler might help.

What speed and timings is the ram at? (use cpu-z)
HT multi is at 3?

I see you've read zebo's guide. What was your max isolated cpu speed?

 

[robertk2012]

downclock the video card and see what happens. My guess is the video card if you are prime stable and have ran memtest.

 

[Drunkentig3r]

I have run Memtest and Prime95-both were stable for hours and hours. I can do everything fine-the only problem is with 3DMark05.