# AMD Athlon 64 X2 5000+ Black Edition @ 2.6GHz stock
# K9A2 Platinum 790FX
# 4GB (2x2GB) OCZ SLI-Edition DDR2 800
# EVGA 7800GT 256MB
# Western Digital Caviar 250GB SATA
# Creative X-Fi XtremeMusic
# Microsoft Windows XP Home Edition SP3 - 32bit and Windows Vista Home Premium SP1 - 64bit
# Corsair 520HX

Christ, here's the scenario. I was overclocking and everything was going fine. I had my PC at 266 x 12 and stable with 1.4v. I decided to try a different equation and set the FSB to 295 and the multi to 10. When I went to boot, the PC froze. Then it wouldn't boot whatsoever. So I removed the battery, waited 30 seconds, reinstalled the battery. PC booted. I reset everything to stock in the BIOS and then tried booting into Windows.

No go. Windows XP would not boot. I had a dual-boot setup going with Vista as well. Vista would boot fine but not XP. So I did a complete reinstall of XP. I'm done with that all now, but when I loaded HWMonitor, I noticed it only shows one core temperature. So I downloaded Prime95, started it and only 1 core was running.

I didn't go beyond the capabilities of the processor, so my only thought is that the increase to the FSB has fried my motherboard. Any thoughts?

Does XP task manager see both cores?
What about VISTA and two cores?

Check CPU-Z.

Prime 95 only uses 1 processor unless you get the dual version or else run two instances.

I use Prime95 version 25.6.1.0 and it loads all four of the cores on my quad, so if that version is used, it should load both cores of a 5000+ BE.

OP- Word of warning gained through 7 years of personal experience. AMD chips very often do not like a high FSB, instead running better on high multipliers. That's the main reason that unlocked AMD chips are so popular. If I'm reading your comments correctly, you now have the computer working with XP, but only one core shows up as working. Is this happening for both XP and Vista, or do both cores show up on Vista? If only one core is showing up on both in Task Manager and on CPU-Z, you probably fried the CPU. If both CPUs are showing up, then the chip is probably fine. In that case, check which version of Prime95 that you have. You may need an updated version to run both cores at once.

Here's an article that explored overclocking the 5000+ BE http://www.insidehw.com/Reviews/CP [...] ition.html Note that the multiplier is raised to 16.5 for the overclock. It can go even higher with the right motherboard and ram.

I doubt that you damaged the motherboard.

I decided to do a complete reinstall of the entire system again. I already installed the system and processor drivers. Still shows one core active. I'm currently installing all of the Windows updates. I wonder if that could have anything to do with it???

Once that is done and I get back home, I'll reinstall Vista and check all of these suggestions out. I'm just so concerned that I killed the processor.

check with cpu-z or amd overdrive how many cores it shows

CPU-Z only shows 1 core active.

Have you got dual core support enabled in the bios?

no option for that. The motherboard was designed for dual-core and quad-core processors only (AM2/AM2+).

Try remounting the CPU, clearing CMOS, unplugging the PSU from the wall socket for about an hour. After that I'm out of ideas.
The one dead core is new to me.

Sounds like a burned chip. I did that once myself years ago. That's part of the hazard when overclocking. Take a look in Task Manager to see if it shows two cores running. You can try the updated Prime95 that tests multiple cores, version 25.6.1.0 and see if it tests both cores or not. If it only tests only one core, or fails while trying to test both cores, the CPU probably is dead. If its within a warranty period, you might try to RMA it. Just don't mention anything about overclocking.

I will be home in about an hour and will give this a shot then. Yeah, the one blown core is baffling me as well. I can't find any other instances of this online.

Nothing worked. Neither AMD or MSI are responding to my inquiries for tech support either.

I say RMA the chip.

Previously there was a conflict between the WinOS dual core patch and the AMD dual core optimizer. If you installed both of them the OS would only recognize one core.

If you indeed installed both - uninstall one of them and you should be good to go ...

Hope this helps.

Fully agree.