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PS Works fine except for Overclocking (TBIRD)??? Any Ideas...

dman

Diamond Member
Nov 2, 1999
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I have an AMD Thunderbird 650MHz which I purchased last week from ComputerGeeks. (Yes, it's a TBIRD 650, it's an OEM Pull from somewhere resold by CompGeeks).

Anyway, I got 2 of them. I put one in a system I was building for someone else and it OC'ed fine to 750MHz.

I then put the second one in a nearly identicle system and it won't overclock. The system that worked fine was in a Stirling El-Cheapo case w/ 250W PS. The system that is giving me problems is an Enlight Medium Tower w/ 250W PS. (The rest of the system consists of MSI K7T Pro 2A Motherboard, Some M.I.C. "TopTech" AMD 1GHz approved Heatsink w/ Large Fan, and PC133 Memory).

The problem with the OC'ing is as follows: Everytime I would set the clock ratio manually to 7.0 or 7.5 it would save, exit the bios, and hang. NOTE: This CPU is NOT L1 Locked--all the bridges are connected from the Factory!

After the hang, I'd Power Off/On and the system would reset back to the default 6.5x. I noticed in the PC Health that the default voltage was 1.77 (a little high) and at one point I found that if I LOWERED the default CPU Voltage from 1.7 to 1.675 (which was a reported 1.75 in the PCHealth) it did let me overclock to 700MHz but not 750MHz (at any manual voltage between 1.6 and 1.8).

So, On a whim, I hooked up a 250w powersupply from another system (another enlight) and it will let me overclock to 750MHz no problems w/ the same settings that would NOT work with the original powersupply.

I'm going to see about getting the powersupply replaced (maybe even upgrading to a 300w), but, it's very odd to me that if it works at normal clock that OC'ing wouldn't make a difference.

I posted this for 2 reasons: 1) To see if anyone has had this happen before and 2) If not, maybe it'll help someone else if they are having trouble OC'ing.


 

dman

Diamond Member
Nov 2, 1999
9,110
0
76
Thanks for the info. I have to wait 'till tuesday to get it replaced (closed over the weekend and busy on monday). Thought I'd share my experience w/ others in the meantime.

BTW, I'm running Seti@Home on it right now (have been for over an hour or so @750MHz) to make sure the CPU and Memory are stable. I find that Seti@Home works best for me in determining system stability. If it'll run for 24hrs w/o a hang I know my CPU and memory are good.





 

TheSentinel

Member
Feb 2, 2001
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Thanks for posting that dman6666.

I bought a cheapo $50 mid tower with a 250W ps for my KT7/Duron700 combo. At higher overclocks (>900mhz), my system was powering off, and I suspected the PS among other things. I didn't want to replace it, because I wasn't sure that was the problem (I have very little disposable income, so I can't just buy stuff on a whim...sniff)

Think I'll get an AMD approved 300W (at least) PS when I get some extra cash...
 

dman

Diamond Member
Nov 2, 1999
9,110
0
76
FYI, I've had some minor prob's with the second 250w power supply now. On occasion the system won't restart (same symptom as before), again, only when the CPU is oc'ed. However, a quick power off and on and the CPU temp is well within range so I don't suspect it's heat. (The CPU auto resets back to 650 when the system hangs and I power off and on.)

When I get around to spending the bucks for a 300w supply I'll post an update to how well it worked. I'm about 90% sure that's the problem. I'm just waiting on a hot deal to come by again on a case w/ 300w supply.

 

dman

Diamond Member
Nov 2, 1999
9,110
0
76
Not sure if it's copper, I suspect not. The die color is green.

The markings on the CPU are:

A0650APT3B
AFEA 0023TPBW
91747180433
(m)(C) 1999 AMD

Assembled in Malaysia.