Overclocking Escapades: socket AM2+ Phenom X3 8750 (non-BE) Toliman

After my experience with the Sempron 145 single core last week I started thinking about the fact that I have a few AM2/AM2+ processors sitting around that I haven't done anything with yet. Tested them a couple years ago, but never tried to overclock them or do any tweaking.

So, this is exploring new ground for me, as I've never really done anything with a Phenom I processor (or anything on AM2/AM2+). Don't know what to expect, results might be good, or might be bad. I'm expecting a lower overclock than AM3 processors though, and probably something closer to what I've come to expect on S939. I've got a couple of Windsor CPU's too, hopefully I'll get to them sometime within the next week or two.

So, let's see what my Phenom X3 8750 Toliman can do. It's the non-Black Edition, so results will probably be lower than the Black Edition. Oh well, it's what I've got.

The board in use is my Asus M2N32-SLI Deluxe (590 SLI chipset), cooling is my Thermalright Ultra 120 Extreme (TRUE), memory is 2x1GB set of Crucial Ballistix .16FD3 with Micron D9 memory chips.

Once I'd gotten the OS and programs installed I noticed the board has an odd issue with the CPU vCore. I had it set at the stock VID of 1.25V in the bios, but CPU-Z, CPUID Hardware Monitor, and the BIOS hardware monitor were reporting 1.3V. So, I've got a vRaise of 0.05V above what is set in the BIOS for some unknown reason. I checked and the setting that applies +200mV to the CPU is turned off, and I didn't find any other settings that seemed related to raising CPU voltage in the BIOS. Since I've not used any other M2N32-SLI Deluxe boards I'm not certain if this is a feature of the model line or just a quirk with my particular board.

So, I started out by trying to find my lowest stable voltage, systematically lowering it until I couldn't get Prime95 to run (it errored out within a couple of minutes at 1.1V in the OS). The lowest stable voltage turned out to be 1.15V, and I ran the Prime95 blend test with that voltage at stock frequency for a four-hour test which ran successfully with no errors and no warnings.

AMD Phenom X3 8750 non-Black Edition overclock settings
2.4GHz (stock): 1.14-1.15V (1.10V) -M2N32-SLI Deluxe
2.5GHz: 1.14-1.15V (1.10V) -M2N32-SLI Deluxe
2.6GHz: 1.18-1.2V (1.15V) -M2N32-SLI Deluxe
2.7GHz: 1.22V (1.175V) -M2N32-SLI Deluxe
2.8GHz: 1.23-1.25V (1.20V) -M2N32-SLI Deluxe
2.9GHz: 1.26-1.28V (1.2375V) -M2N32-SLI Deluxe
3.0GHz: 1.36-1.38V (1.325V) -M2N32-SLI Deluxe, 1.312v (1.325v) (idle: 17°C) (load: 33°C) -GA-MA790X-UD4P
3.1GHZ: 1.44v (1.45V) (idle: 18°C) (load: 34°C) -GA-MA790X-UD4P

The load temperatures are surprisingly low, I expected them to be in the 40-50°C range, but under a full load with Prime95 the CPU was hanging around 28-32°C. Room temp is around 25°C.

As for the board my M3N does the same thing with the added voltage. Never did figure out why just adjusted accordingly. I am surprised at how much cooler that runs than my 9850 Agena. That thing is like a small nuclear reactor. I also have a 9150eX4 that isn't a BE. The highest I could get the reference clock was around 240. Maybe with the 590 chipset you'll have a bit more luck.

Johan45 said:

As for the board my M3N does the same thing with the added voltage. Never did figure out why just adjusted accordingly. I am surprised at how much cooler that runs than my 9850 Agena. That thing is like a small nuclear reactor. I also have a 9150eX4 that isn't a BE. The highest I could get the reference clock was around 240. Maybe with the 590 chipset you'll have a bit more luck.

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Oh, well that's good to know. Wasn't sure if the voltage issue was an isolated incident or was common.

I'm not sure if the temperature sensor is giving faulty readings or if this thing just really runs cool for some unknown reason. I had a Phenom X4 9750 a while back, and I remember it running a little warmer than this (at stock speed and voltage), I think it hit at least 40°C under load. It definitely gives faulty values at idle though, since it reports 18-23°C at idle, when the ambient temperature of the room it's in is 24-25°C.

As far as performance, this thing isn't great. With this triple-core when I'm running Prime95 blend the system gets very slow and unresponsive. If I try to load a program (CPU-Z for instance) I have to wait for 30 seconds to 2 minutes for it to actually start loading. That's just disappointing, because with a Sempron 145 single-core CPU in my AM3 system I could turn on firefox and surf the web while still running Prime95 with no noticeable slow-downs or reduction in performance. I honestly don't think I could stand to run this system in a daily-usage scenario, I'd be annoyed with it really quickly.

Gotta get the cpu speed closer to 3ghz and it'll be decent. Figure it this way, 3ghz is like a 3.8ghz current FX (roughly) being the transistor count per core is actually higher on the Phenom.

Get it clocked up Tech! I'd think 2.8ghz would be a reasonable speed to aim for with not too much voltage. Maybe like 1.35v-1.4v should get you close up to 3ghz if you notice now at 2.4ghz 1.15v isn't very much unless you have some green enabled.

Also, with older systems, you can search around for older versions of AOD to see if you get different OC options within the program, but maybe not stability, or perhaps increased software OC stability.

ShrimpBrime said:

Gotta get the cpu speed closer to 3ghz and it'll be decent. Figure it this way, 3ghz is like a 3.8ghz current FX (roughly) being the transistor count per core is actually higher on the Phenom.

Get it clocked up Tech! I'd think 2.8ghz would be a reasonable speed to aim for with not too much voltage. Maybe like 1.35v-1.4v should get you close up to 3ghz if you notice now at 2.4ghz 1.15v isn't very much unless you have some green enabled.

Also, with older systems, you can search around for older versions of AOD to see if you get different OC options within the program, but maybe not stability, or perhaps increased software OC stability.

Click to expand...

I'm working my way up there, just takes time. I don't want to just set some arbitrary voltage settings though, I want to know the actual minimum stable voltage for a given overclock level so that I can have a reference later if I need a specific overclock level (for whatever reason). Sure it takes longer, but I feel it is a more thorough method of testing. Obsessive compulsive? Maybe a little.

Even at 2.6GHz and fully stable it's slow and unresponsive at times, which is something odd that I've never really encountered before, except for maybe on a S754 single-core.

I'm testing with Prime95 for 2.7GHz now (1.2V in the OS at the moment).

Well, I've run into some sort of weird issue here.

For some reason something on my board is reporting temps up to 124°C/255°F. Apparently the set of mosfets below the CPU socket as far as I can tell, as from just feeling around the board that was the only area that was noticeably hot. I'm not sure they really are that hot, but putting my hand on the heatsink it felt like it was approaching the heat on the surface of the sun.

Now, with that in mind I am running into a strange issue with the PC just shutting down within 1-3 minutes of firing up Prime95 when I was testing at 3GHz.

To test whether this was a heat issue or not I dismantled the rig from my test bench and replaced the paste on the NB and SB (unfortunately couldn't replace pads on mosfet areas, as I have no spare thermal pads on hand). Then, I slapped a fan on the lower mosfet section, which unfortunately didn't help anything as I'm still at 124°C according to CPUID Hardware Monitor, and I could probably fry eggs on that heatsink. The CPU is cool as a cucumber though, and I'm maxed out at 38°C so far.

So, after that failed to help I reduced the CPU multiplier from 12x down to 10x to see if it was an issue with the bus speed itself. FSB/Bus Speed/HT Speed still at 250MHz, HT Link is at 1000MHz, RAM speed at 833.4MHz, CPU vCore is still at the same 1.34V (in OS) it was at for 3GHz, and all other voltages are unchanged. I've been running Prime95 Blend for about 20 minutes now, and it hasn't crashed, shut down, or blue screened.

My question is why would it be just straight shutting down? Not enough vCore? Not enough of some other voltage? It's certainly not an issue with the power supply, because the voltages of the rails are well within specifications. I'm a little unsure on this one, given my limited experience with AM2, and the fact that I've never had a system just power itself down during a Prime95 test.

Heat doesn't seem to be the issue, as I'm still at the same temperature and it's still running at a lower clock speed.

And on an unrelated note, should I be concerned at all about the "NB Frequency" I see on the Memory tab in CPU-Z? I'm at 2250MHz at the moment.

Okay, seems like it's tripping the OCP or OVP on my PSU.

I found an article online talking about it sometimes being necessary to run these Phenom chips on AM2+ boards rather than AM2 boards due to AM2+ having a better power section to handle the higher amperage and voltage that these require to be stable when overclocked. This seems like a legitimate argument, since on my board I don't have the 8-pin EPS connector, I'm limited to the 4-pin 12V CPU power connector, which I'm guessing isn't able to deliver the amperage, wattage, or voltage that the CPU is demanding to remain stable.

That seems to be what I'm running into, because I'm drawing 250 Watts+ and over 2.5 Amps at the wall with Prime95 running. And as soon as the system hits its max wattage and amperage draw, it shuts down and/or reboots. It doesn't matter what voltage I supply to the CPU, I went up over 1.45v, and it still wasn't stable.

At 2.9GHz though, I'm at 2.14 Amps and 245 Watts max at the wall according to my Kill-A-Watt meter, and everything is perfectly stable.

This is one problem I really didn't expect to run into with this board, since it seemed to be well built and has a decent power section for the CPU. Apparently it's just not good enough to run an overclocked Phenom CPU though.

This is one reason why you should not use a cheap board that doesn't have a good enough power section for overclocking a CPU with a high power draw. I used an AM2 Asus M2N32-SLI Deluxe board because it was what I had on hand and I don't currently own an AM2+ board, that may have been a mistake on my part, as I didn't know just how much wattage and amperage this CPU needs.

Finally revisited this after a year and-a-half. Did see about a 200MHz gain in CPU speed after upgrading to a more robust motherboard in the AM2+ socket type.

The liquid cooler probably helped a bit too.

This looks sharp. Nice build Tech.

Nice, I assume those are the GB numbers?? Looks good TT