AMD FX-8150 "Bulldozer" CPU Review - PAGE 4

The FX-8150 will be pitted against the Phenom II flagship in both stock and overclocked states. It supposedly has lots of overclocking headroom so the comparison will be interesting. Both will be running on the ASUS Crosshair V Formula reviewed a few weeks ago, and will be cooled by a Cooler Master V8 heatsink. The now three years-old Intel Nehalem architecture and the newer Sandy Bridge meanwhile stand for the blue side of the fence. All test setups have the Turbo feature disabled to increase the score consistency.

Test Setup

AMD FX "Zambezi" (Socket AM3+)

• AMD FX-8150 processor
• ASUS Crosshair V Formula motherboard
• XFX Radeon HD 6970 videocard
• Seagate 750GB 7200.11 hard drive
• Mushkin Joule 800W power Supply
• 2x4GB Mushkin DDR3-1600 8-8-8-24-1T memory
• Corsair Graphite 600T chassis

Comparison Setups

AMD Phenom II "Thuban" (Socket AM3)

• AMD Phenom II X6 1100T processor
• ASUS Crosshair V Formula motherboard
• XFX Radeon HD 6970 videocard
• Seagate 750GB 7200.11 hard drive
• Mushkin Joule 800W power Supply
• 2x4GB Mushkin DDR3-1600 8-8-8-24-1T memory
• Corsair Graphite 600T chassis

AMD Phenom II "Deneb" (Socket AM3)

• AMD Phenom II X4 980 processor
• ASUS M4A89GTD PRO/USB3 motherboard
• XFX Radeon HD 6970 videocard
• Seagate 750GB 7200.11 hard drive
• Mushkin Joule 800W power Supply
• 2x4GB Mushkin DDR3-1600 8-8-8-24-1T memory
• Corsair Graphite 600T chassis

Intel Core i7 "Bloomfield" (Socket 1366)

• Intel Core i7-920 & i7-965 processor
• MSI X58 Platinum motherboard
• XFX Radeon HD 6970 videocard
• Seagate 1TB 7200.11 hard drive
• Mushkin Joule 800W Power Supply
• 3x4GB Mushkin DDR3-1600 8-8-8-24-1T memory
• Corsair Graphite 600T chassis

Intel Core i7 "Sandy Bridge" (Socket 1155)

• Intel Core i5-2500K & i7-2600K processor
• Intel DP67BG motherboard
• XFX Radeon HD 6970 videocard
• Seagate 1TB 7200.11 hard drive
• Mushkin Joule 800W Power Supply
• 3x2GB Mushkin DDR3-2000 9-11-10-28-1T memory
• Corsair Graphite 600T chassis

Benchmarks

Oddly enough, Crysis Warhead would not run on the AM3+ setup so it will not be used. Hopefully the problem will be found and the game benchmarking tool will be used again. Three of the following benchmarks will also be used for testing the Turbo capability.

• SiSoft Sandra Professional
• 7-Zip
• PCMark Vantage & 7
• Handbrake
• POV-Ray
• Cinebench
• Far Cry 2
• Colin McRae DiRT 2
• Call of Juarez
• World in Conflict
• Lost Planet
• 3DMark 11
• Power Consumption

Overclocking

After what was witnessed at the Bulldozer conference, great numbers were expected from this FX-8150; with the self-contained water cooling kit, this baby ran a Unigine benchmark all day long at 4.8GHz on all eight cores. Had it been tested with a stability benchmark though? Here at Neoseeker, every overclock has to sit through such a test for one hour, which is still pretty generous. In previous AMD reviews, OCCT Perestroïka worked pretty well for catching instability in the cores and IMC. With the new core, it didn't perform as well compared to Prime95, because the processor did not heat up as much, and it turns out Bulldozer enjoys cooler temperatures when it comes time to overclock. Furthermore, the self-contained water cooler that can be purchased along the processor, thus replacing the standard heatsink, was not received in time for this overclocking session, so as mentioned earlier the Cooler Master V8 heatsink will be used instead.

As will be shown later, the chip is pretty environmentally-conscious at stock levels, but at some point the heat builds up quite rapidly. The power usage of the K10 seemed to increase less abruptly, but at the same time it was much less tolerant with higher temperatures; at around the 55 to 60^oC mark, it really began to show off decreased stability. This particular FX-8150 sample seemed to be able to get as hot as 75^oC. Obviously, the poor Cooler Master V8 had quite a hard time keeping up, and definitely limited the overclock.

Nevertheless, Bulldozer is overclocked the same way as Phenom II. More precisely, like the Black Edition Phenom IIs. In fact, all processors in the FX series are going to be unlocked. With Neoseeker's sample, the memory controller didn't seem as friendly, maximizing at around 2650MHz for an extra 200mV. The memory compensated for this though, as it just kept climbing without any fuss. ASUS' own utility was used to for monitoring the voltages and temperatures.

All in all, these are the final settings used:

• Reference Clock of 236MHz resulting in 236.8MHz
• CPU Ratio of x19 resulting in 4499MHz
• Memory Ratio of 3:14 resulting in 2210MHz
• CPU/NB Ratio of x11 resulting in 2605MHz
• CPU Voltage of 1.39375V
• CPU/NB Voltage of 1.30V

Seeing how the FX-8150 starts to heat up at 4.5GHz, the water cooler should really help to maximize the overclocks. It remains to see if the premium commanded by the bundled water cooler is actually worth it compared to just buying a stand-alone cooling system. Neoseeker will look into this in another article.

The overclocks on air cooling can be summarized as follows:

Update 11/10/15: The Crosshair V Formula has a VRM temperature protection mechanism. With power-hungry processors such as an overclocked FX-8150, under stressful situations, the mechanism triggers the throttle of the processor. Putting a fan over the VRM heatsink prevents this, and actually also has a great impact on the processor temperature. With the Asetek self-contained water cooler provided along the FX-8150, at the overclock presented above, the processor would top at 61^oC instead of 75^oC. In the initial testing, this protection mechanism was not observed because the VRMs were kept cool enough. It can be disabled in the BIOS with the option "VRM Temperature Protection", but it is obviously not advised.