AMD Phenom II X2 550
Biostar TA790GX A3+
4 GB DDR3 RAM@1333MHz
Nvidia GeForce 250 GTS 1GB
Western Digital Caviar 160 GB (going to be replaced with a Caviar Black 640 GB w/32MB Cache)
Rosewill RP500 500W PSU (going to be replaced with a 600W PSU)
Windows 7 x64 Ultimate
Well, after a month of running my process as a dual core I've been trying to unlock the quad and have been somewhat successful with a few oddities. My old Phenom II X2 was unlocked, but it went bad (motherboard went out and took the processor with it) so the CPU I have now is actually a replacement. I had a 555 Deneb Black Edition, but AMD sends me a 550 Callisto. Weird.
Anyway, I went into the bios and turned on the ACC function to all cores with core leveling at -2%. When I had the Deneb BE I had remember I had to set the HT link speed to 1.6GHz for it to work stable as a quad so I do that again. Save changes in bios, reset, and Windows boots up. So far everything is look good. Load CPU-Z and it's recognized as a X4 B50 quad. So, I decide to re-run the Windows 7 experience assessment. Everything is working and I'm monitoring my CPU temps ranging between 45-50*C, but the oddity comes into play when it gets to the CPU assessment subsection. Screen goes black and the computer just reboots itself. This happened three times, it cannot complete the assessment as a quad. For safety reasons I have the ACC disabled and the processor back as a dual core.
So, I'm trying to figure out what is happening and why I can't get it to run as a quad.
First, I thought it might be the stock cooler and the CPU temps. Thing is when I ran the assessment again as a dual core the load temps were pretty much the same as when it had been a quad so temperature shouldn't really be a factor of why the quad can't complete the assessment. I also don't think there is much of a difference (if any) between the dual core stock cooler and the cooler the quad uses. I wasn't planning on overclocking or anything, just to run it as a quad.
Second, I began to wonder if my 500W PSU can't handle the processor as a quad, but this is the same PSU I was using when I had my 555 Deneb BE unlocked and didn't have any issues back then. Of course I have a 600W PSU I"m going to be installing when the rest of my parts arrive so if it is a power issue then it should be resolved when I install the new power supply.
Third, I've taken into account it might have something to do with my hard drive itself. It's an older drive I've had forever and a day, but I've become under the impression that it might be reaching the end of its life cycle. It could possibly have bad sectors. I'm not exactly sure, but if the issue with the quad has anything to do with the hdd then hopefully it will be resolved with my new drive and a fresh/clean Win7 installation.
Fourth, I considered the possibility it might have something to do with the corrupt Win7 installation on my hard drive. For whatever reason Win7 has gone bad, but is still working. I know this because a while back I was getting system crashes and BSODs so I tried loading up event viewer to check the system error dump files and the minidumps, but the service wasn't running nor could I get it to start. So, I did a "sfc /scannow" command in cmd to check the integrity of the Windows file system. SFC reports corrupt files (namesly iassdo.mui.dll and a few others) so I can't recall how many times I've taken ownership of the bad files as reported by SFC and replaced them with the originals from my Win7 DVD, but now matter how many times I do it files are always being reported as corrupt by the system file checker everytime I run the scan. A lot of the time it's the same files too. It's the most unusual problem because it doesn't impact system performance at all as all of games and applications run perfectly fine. They don't lock up or crash. Still, it makes me wonder if the compromised integrity of my Win7 installation might be affecting my processor as a quad. I know I will have to reinstall Windows, but I'm waiting until my new hard drive arrives before I go through the trouble of reloading everything.
I'm confused as hell and can't figure out how to keep the quad. I can unlock it and boot into windows just fine (haven't tried running any apps like 3DMark06 yet), but if I run the Win7 assessment then it reboots the computer when it gets to the CPU assessment.
Well, you forgot to check one thing: Something you should have learned in the first place before even attempting core unlocking: the reason why AMD locks cores.
AMD started back with the original phenom x3. They got the idea that "hey, this quad core CPU has a bad core. But wait, instead of throwing it out, we'll disable the bad core and sell it as an x3". So of course, with these processors, if you unlock a core, it is not up to spec. It could be anywhere from only running stable at much lower clocks to just plain dead. Well, now everyone wants to buy an x3. But there aren't enough bad quad cores. So AMD disabled the core or cores of a perfectly good quad core to get an x2 or an x3 to med demand. People find this out and realize that some but not all dual and tri phenom II's have a perfectly good third and fourth core. So people start unlocking.
It sounds to me like the CPU AMD sent you actually did have two bad cores. You could, however, try unlocking only one additional core and see if it works. You could also try running the quad core at lower clock speeds or a higher voltage.
Have you done any kind of a stability test? Sounds like it is crashing because the cpu isn't stable, and like enzo matrix already stated, the only reason AMD sells Phenom II X2/X3 parts is because an unknown percentage of them actually have defective cores that won't function properly when unlocked. You bought an X2, you should only expect to have 2 working cores and consider any additional cores a bonus.
Well, I unlocked it as a quad again and went into windows, but this time I didn't run the Win7 experience assessment. I installed AMD Overdrive and set the HT multiplier to x10 (for HT link = 2 GHz). Instead of doing the Win7 experienced I ran 3DMark06 and it passed all the test, even the CPU assessment, without error or issue.
Next I loaded up prime95. Everything was going good and it was passing all the tests, but the processor temps shot up to 70*C and my hardware monitor alarm kicked in forcing a shutdown. The quad was passing Prime95, but the under load temps had gotten above the safe temp threshold. When I rebooted back into windows, still as a quad, I went back and re-ran the Win7 experience test. It got further than it normally has, but a popup message appeared saying: "your cpu fan isn't working! shut off your system and check it!". At the time of the popup box I looked at my hardware monitor and my fan was indeed working and the under load processor temp was only 45*C at the time the message dialogue box appeared. I clicked OK on the dialogue and the computer rebooted shortly after.
All of this leads me to believe that the cores are in fact not defective, but it is instead a temperature issue. As far as I know there aren't any differences between the stock coolers shipped with the quads or the dual cores so why the stock cooler can't keep it running as a stable quad not overclocked is beyond me. This might also have to do something with the power supply and the unlocked processor having a heavier power requirement (125W quad vs 80W dual core). Of course this should be resolved when I install the 600W psu.
I bet if I could resolve the temperature issue I could keep it running as a quad. I've heard of people having their unlocked quads running at normal clocked speeds with their stock coolers, but for whatever reason I can't do the same.
It doesn't sound like you are going to get there on the stock cooler anyway but I would try setting the the cpu voltage manually to try and find the lowest stable amount. Also remember the core temps are disabled when you unlocked the cores so the temp you are reading is from the motherboard and most likely around 10C lower so I think you should not run at any setting that goes over 60C or you will fry it very quickly. My unlocked 550 max temp is 50C in prime 95 and running at 3.55GHz with a coolmaster hyper tx3.
I'm using my cooler master GeminII again and I bought a new fan for it rated at 110 cfm. I'm also using a better thermal compound, Tuniq TX-2, which keeps my 550 at 27*C idle and 35-40*C under load as a dual core.
The core temps for the third and fourth cores may be disable through the mainboard hardware monitor, but I'm using a third party program to read my temps. Also, an addition of 10*C is inconsistent and doesn't make much sense. If my dual core idles at 28*C then I'm roughly averaging 14*C per core, but if I unlock it to a quad and only add 10*C then there is a discrepancy. Adding only 10*C means I'm averaging only 5*C for the third and fourth core which doesn't make much sense. Then there's the fact if I unlock the quad, boot into windows, load up my hardware temp and it reads 28*C that would mean it's closer to 38*C idle. Something wrong with that picture, not even my 555 BE had that high of idle temps when unlocked. A processor shouldn't run that hot, not even with a stock cooler, while idling simply because of the low amount of heat it generates when it is idle. If it idles that hot then there is something wrong with the cooler. When you say your max temp is 50*C in prime95 is that with or without the added 10*C?
I'm also trying to figure out which voltages should I play around with? Should I focus more on the CPU VID or should I be raising the NB VID as well? What I have been doing is raising the NB VID .05V and if that doesn't work then I'll raise the CPU VID .05V to compensate. I noticed that the stock voltages (CPU VID 1.35V, NB VID 1.10) have a .25V difference between them and I've been wondering if I should preserve that ratio.
Right now I have it unlocked as a quad again with the HT link multiplier set to 10x, the CPU VID is 1.40 and the NB VID is 1.20 in AMD OverDrive. I've been running prime95 for about twenty minutes my max temp is 54*C thus far as read from my hardware monitor (that's not adding 10*C) and it seems to be stable up to this point. All four cores have passed the 1024K and 8k iterations torture self tests up to this point. I'm going to run prime95 for another hour to hour and a half, and if everything is going good till then I can be pretty sure the quad is stable. If not then I'll raise the CPU VID to 1.45V, keep the NB VID at 1.20V, and try again. So, we'll see how it goes.
I have the same mobo and cpu with modded bios added I unlocked all 4 cores....ran great at stock,so I bumped it back up to 3.78 (what I had it flawlessly clocked to at two cores,from 3.1ghz) the everest ultimate edition tests ran great and holy Shiz what an increase!!! ran the windows score test thing and it went from 6.5 on cpu @ 2cores to 7.3 @4, anyway everything ran great, I could even up my memory speed as before the unlock i couldnt hit 1600 on memory....ok heres the crap part, I ran dirt2 and the game is messed up, the screen twitches and the sound is a little tear-y, ran Mafia II and it immediatly crashes to desktop, also with cool and quiet enabled with all 4 cores, windows will crash about 2 mins after the desktop is loaded....I was really happy cuz it was seriously flying but if I cant do gaming its poitless, im running onboard HD3300 video idk if that has anything to do with it (all these games ran fine at 2 cores +oc to 3.78