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The Athlon X4 750K edges in on the action
AMD may not be competing too vigorously against Intel's high-end CPUs these days, but when you get into budget territory—and especially unlocked CPUs with lots of bang for the buck—then you've just stepped into AMD's wheelhouse. AMD's current answer to the Anniversary Edition Pentium is the Athlon X4 750K, an unlocked quad-core processor selling for $79.99 at Newegg. AMD was kind enough to provide us with one to test against the Pentium G3258.

The X4 750K is based on Trinity silicon, which means it's a generation or two behind the latest Kaveri chips, depending on how you're counting. Still, the 750K's dual "Piledriver" modules are pretty well suited for this mission. With four integer cores, two FPUs, dual 2MB L2 caches, a 3.7GHz base clock, and a 4GHz Turbo peak, the Athlon X4 brings somewhat beefier hardware to this fight than the Pentium does. The Athlon X4 officially supports DDR3 memory speeds up to 1866 MT/s, too.

In keeping with its general M.O., AMD has left this chip's special features largely intact, so instructions like AES-NI for accelerated encryption are fully available. That's nice. The one exception is built-in graphics. The Radeon IGP has been disabled in the Athlon X4—not that we're likely to miss it with a discrete graphics card installed.

Even without the Radeon IGP, AMD is clearly willing to give you more hardware for your money at this price. There's a trade-off, though, as with most AMD CPU offerings these days. The X4 750K's default TDP rating is 100W—nearly double that of the Pentium G3258. That's the starting point, and the 750K will likely draw even more power once it's overclocked.

To test the X4 750K's potential, I dropped it into an Asus A88X-Pro motherboard and attached a massive Cooler Master tower.

With a little tweaking, the 750K was soon running reliably at 4.5GHz and 1.425V.

I tried pushing as high as 1.525V in an attempt to get it stable at 4.6GHz, but that wasn't meant to be. Consistently, one particular thread in our Prime95 test would exit with a computational error. One of the four cores evidently wasn't happy at higher clocks. 4.5GHz isn't bad, but it's a little less than the 4.8GHz we reached with the Richland-derived A10-6800K. Ah, well.

I used the AMD Overdrive utility to monitor the CPU's state while overclocking. This utility doesn't report absolute CPU temperatures, but it said there was still 32°C worth of "margin," or headroom, in the overclocked 750K when running Prime95. The entire Athlon X4 750K test rig pulled 163W at the wall socket during this same workload.

AMD's Piledriver can't match Intel's Haswell clock for clock, but at 4.5GHz, the Athlon X4 750K ought to give the Pentium G3258 a run for its money in multithreaded tests. Right? Let's have a look.

Our testing methods
The test systems were configured like so:

Processor AMD FX-8350 AMD A10-7850K Athlon X4 750K
Motherboard Asus Crosshair V Formula Asus A88X-PRO Asus A88X-PRO
North bridge 990FX A88X FCH A88X FCH
South bridge SB950
Memory size 16 GB (2 DIMMs) 16 GB (4 DIMMs) 16 GB (4 DIMMs)
Memory type AMD Performance
Series
DDR3 SDRAM
AMD Radeon Memory
Gamer Series
DDR3 SDRAM
AMD Radeon Memory
Gamer Series
DDR3 SDRAM
Memory speed 1600 MT/s 2133 MT/s 1866 MT/s
Memory timings 9-9-9-24 1T 10-11-11-30 1T 10-11-11-30 1T
Chipset
drivers
AMD chipset 13.12 AMD chipset 13.12 AMD chipset 13.12
Audio Integrated
SB950/ALC889 with
Realtek 6.0.1.7233 drivers
Integrated
A85/ALC892 with
Realtek 6.0.1.7233 drivers
Integrated
A85/ALC892 with
Realtek 6.0.1.7233 drivers
OpenCL ICD AMD APP 1526.3 AMD APP 1526.3 AMD APP 1526.3
IGP drivers - - -

Processor Core i5-2500K Core i7-3770K Core i7-4770K
Core i7-4790K
Pentium G3258
Motherboard Asus P8Z77-V Pro Asus P8Z77-V Pro Asus Z97-A Asus Z97-A
North bridge Z77 Express Z77 Express Z97 Express Z97 Express
South bridge
Memory size 16 GB (2 DIMMs) 16 GB (2 DIMMs) 16 GB (2 DIMMs) 16 GB (2 DIMMs)
Memory type Corsair
Vengeance Pro
DDR3 SDRAM
Corsair
Vengeance Pro
DDR3 SDRAM
Corsair
Vengeance Pro
DDR3 SDRAM
Corsair
Vengeance Pro
DDR3 SDRAM
Memory speed 1333 MT/s 1600 MT/s 1600 MT/s 1333 MT/s
Memory timings 8-8-8-20 1T 9-9-9-24 1T 9-9-9-24 1T 8-8-8-20 1T
Chipset
drivers
INF update 10.0.14
iRST 13.0.3.1001
INF update 10.0.14
iRST 13.0.3.1001
INF update 10.0.14
iRST 13.0.3.1001
INF update 10.0.14
iRST 13.0.3.1001
Audio Integrated
Z77/ALC892 with
Realtek 6.0.1.7233 drivers
Integrated
Z77/ALC892 with
Realtek 6.0.1.7233 drivers
Integrated
Z97/ALC892 with
Realtek 6.0.1.7233 drivers
Integrated
Z97/ALC892 with
Realtek 6.0.1.7233 drivers
OpenCL ICD AMD APP 1526.3 AMD APP 1526.3 AMD APP 1526.3 AMD APP 1526.3

They all shared the following common elements:

Hard drive Kingston HyperX SH103S3 240GB SSD
Discrete graphics XFX Radeon HD 7950 Double Dissipation 3GB with Catalyst 14.6 beta drivers
OS Windows 8.1 Pro
Power supply Corsair AX650

Thanks to Corsair, XFX, Kingston, MSI, Asus, Gigabyte, Intel, and AMD for helping to outfit our test rigs with some of the finest hardware available. Thanks to Intel and AMD for providing the processors, as well, of course.

Some further notes on our testing methods:

  • The test systems' Windows desktops were set at 1920x1080 in 32-bit color. Vertical refresh sync (vsync) was disabled in the graphics driver control panel.

The tests and methods we employ are usually publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.