AMD Phenom X4 9750 Quad Core CPU Review

R-E-S-P-E-C-T

To put this powerhouse through its paces we selected MSI’s 790X - K9A2 CF motherboard, this motherboard is a 4 phase (really a 3+1) which uses the older 4pin 12v aux connector. Even thought it is rated for 125W TDP CPUs our 9750 popped two of the 4 MOSFETs like they were Chiclets after only a few minutes or so of use. Believe it or not, Windows was not even fully installed, it got to the first reboot portion and upon reboot there was a pop, at which point we KNEW what that sound meant and jumped up to turn off the PSU. Unfortunately, before the switch could be flipped, a second pop occurred and a 4 inch flame erupted from one of the MOSFETs. Luckily this system was in an open bench so putting out the fire was relatively easy. Lesson of the day: “When Thou Art Dealing With Phenom’s Thou Shall Not Skimp On Thy Motherboard!”

After this occurrence we rethought our AMD AM2+ test bed setup and decided to go with a more heavyweight board. We took a long hard look at the various motherboards that would fit our wants/needs/requirements and the deciding factor came down to BIOS options. While there are many great companies making excellent AM2+ motherboards (including MSI) one stands above the rest when it comes to shear number of possibilities available to an enthusiast in its BIOS. We of course are alluding to none other than DFI; DFI has a well deserved reputation for offering the most complete BIOS options of any company.


To be more specific on which of their mainboards we went, with we went for the full meal deal version of the their 790FX chipset based motherboard line. The DFI LANPARTY UT 790FX-M2R is a wonderful board with a great chipset and we were very honored to have its horsepower made available to us. It is too bad that our test sample 9750 was not a Black Edition (i.e. it has a locked multiplier) as this DFI board would more than likely have been able to eek out a higher OC if we were able to do more than adjust the HTT and voltages.


For most tales of woe this would be the happy ending; as this is reality, and Reality/ Karma /Mr. Murphy has a fond love of kicking you when your down this was just the end of the beginning. For anyone who has read our recent review of the OCZ Vendetta 2 CPU cooling solution already knows, we had selected this cooler as a our AM2+ test bed cooler. It is a great cooler in its own right and when paired with a Noctua NF-P12-1300 fan it becomes a truly legendary performer…of Intel Quad 775 CPUs.

With this combination at stock speeds and voltages our 9750 idled in the mid 30s and topped out around 65°C +/- a few degrees. This while hot, was still acceptable as we of course had disabled Cool n Quiet and the Phenom’s four CPUs were running full speed all the time and most importantly ambient temperature was 25°C. Then we began our first round of Overclocking and things took a real turn for the worse.

At anything above 2.5GHz the system would run fine and then during stability testing shutdown (no blue screen, no errors, just a hard reboot). At first we just thought this chip was a terrible overclocker and increased the juice slightly. However, instead of making the system more stable this gave the appearance of making the system LESS stable as it would crash even faster. This was a truly “Eureka” moment and we went back into the BIOS and changed the CPU Overheating protection from 75°C to disabled.


One of the biggest problem with the Phenoms and overclocking is that unlike Intel C2D’s, Phenom’s just give an approximation of their temperature; thus Core Temp only shows one temperature and in our case it was undervaluing this temperature (this is a known issue with Phenoms so while we expected it to be off we were expecting it to be at least close!).

While we were in the process of tweaking the BIOS and removing the overheating safety we also decided to beef up the cooler as the Vendetta 2 + Noctua was clearly not able to handle the thermal loads. We knew the Vendetta 2 had the potential so instead of swapping it out we rummaged around in the Ye Olde Parts Bin and found a 120x38mm Panaflo 103CFM fan which works fine except it has a blown PWM and thus is either ON or OFF. We also took the precaution of lowering ambient temp back to 20°C. This potent new combination lowered stock temperatures to the mid 20s and low 50s for idle and load temperatures respectively. Armed with our new and improved Vendetta 2 we restarted our OC’ing phase with renewed hope and vigor.

You can read how our OC’ing went in the Overclocking Performance Results section. Before we continue we would like to point out that these Phenoms are truly heavy weight performers which unfortunately gives us flash backs to the days of certain 930 Ds with it’s fireball predisposition. Quite literally the thermal load was so high during initial overclocking that the top of the heatpipes became discolored and mottled in appearance. This tells us that these heatpipes were pushed to their limits and maybe even a little past their limits!