AMD Phenom II X4 955 Black Edition

While the higher power consumption is a slight concern, the X4 955 proves that AMD is back in the performance game and ready to play hard ball. Bring on the next generation.

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Craig was sucked into the endless vortex of tech at an early age, only to be spat back out babbling things like "phase-locked-loop crystal oscillators!". Mostly this receives a pat on the head from the listener, followed closely by a question about what laptop they should buy.

AMD has been targeting mainstream computing for a while now.

Its combination of good performance for affordable price has seen it claw back into the graphics market with its most recent generation of cards, and now it looks positioned to do the same with the CPU side of the business. While it doesn't intend to challenge Intel's top performing Core i7 CPUs for now, AMD's latest, the Phenom X4 955 Black Edition (BE), launches a broadside across the bow of Intel's mainstream quad-core processors — in particular the Core 2 Q9550.

Black boxed bliss (Credit: AMD)

Based on AMD's AM3 socket, the 955 is a quad-core, 45nm process CPU running at 3.2GHz, as a result of a 16x multiplier on top of a 200MHz bus. It has 6MB shared L3 cache, along with 64+64KB data + instruction L1 and 512KB L2 cache per core. Being a flagship chip, it's quite a power sucker, at 125W TDP. Being a Black Edition chip, it's also multiplier unlocked — and this combined with the split plane voltage introduced on AM2+ should mean some fairly decent DIY speed increases.

Moving to 938-pin AM3 means a few things; firstly DDR3 support, and secondly the 128-bit integrated memory controller has had its Hypertransport link bumped from 1.8GHz on AM2+ to a healthy 2.0GHz. The processor should be backwards compatible with AM2+ boards, but be warned you'll only be able to use DDR2 on these, and your vendor will need to have released a BIOS update to support the CPU.

Test configuration

We've compared the Phenom II X4 955 BE against its price match competitor from the Intel camp — the Core 2 Q9550. Let's take a closer look at the CPUs on test.

AMD Phenom II X4 955 Intel Core 2 Q9550
Clock Speed 3.2GHz 2.833GHz
Multiplier 16 8.5
Multiplier unlocked Yes No
Bus speed 200MHz 333MHz
Memory controller link 2000MHz 1333MHz
L1 cache 64+64KB data + instruction per core 32+32KB data + instruction per core
L2 cache 512KB per core 6MB per dual-core
L3 cache 6MB shared N/A
Socket AM3, AM2+ LGA775
Memory supported DDR3/DDR2 DDR3/DDR2
Process 45nm 45nm
Supported instructions MMX, SSE/2/3/4a MMX, SSE/2/3/4.1
Vendor specific instructions AMD64, Extended 3DNow!, Cool'n'quiet, NX bit, AMD-V Intel 64, iAMT2, EIST, XD bit, TXT, Intel VT
TDP 125W 95W

Intel's been outperforming AMD for clock ever since the introduction of the Core architecture, while AMD has hit back on the price platform. AMD's jump to 45nm is finally seeing it claw back some market share, and it's not so much this generation as next generation where we're likely to see some interesting things happen. Let's take a look at the test benches that put the grill on both the Intel and AMD sides.

Platform one Platform two
CPU AMD Phenom II X4 955 BE Intel Core 2 Q9550
Heatsink Thermalright Ultra Extreme 120 Thermalright Ultra Extreme 120
RAM 2x Corsair 2048MB XMS3-1600, 11-11-11-30-41-1T 2x 2048MB Corsair XMS2-1066, 5-5-5-15-22-2T
Motherboard Asus M4A79T MSI P7N Diamond
Graphics card Asus 8600GT Silent (Driver 186.18) Asus 8600GT Silent (Driver 186.18)
OS drive Intel X25-E 32GB Intel X25-E 32GB
Storage drive Seagate Barracuda 7200.11 1.5TB Seagate Barracuda 7200.11 1.5TB
Optical drive Asus DRW-22B1ST Asus DRW-22B1ST
Operating system Windows Server 2008 SP2 64-bit Windows Server 2008 SP2 64-bit

Note that the Core 2 Q9550 is running with DDR2 compared to the Phenom II X4 955 BE's DDR3 — and although the P7N Diamond is certified for DDR2-1333, it will not run higher, and despite loosening the timings the RAM would not run faster than 1066MHz on this board. As such, we've opted to provide benchmark scores on the Phenom II platform for both the stock 1600MHz DDR3 and downclocked to 1066MHz.

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leeory posted a review   

I just love beause it makes me
yappy. Wood not own anything
else. Untill the 995.


Paveguts posted a comment   

The Good:Smooth Hardware swap / transition, text book set up, OC never easier.

The Bad:Has the speed and power to go back in time...

I've installed the 995 in an Asus M4A78T-e w/ 8 gb of Corsair DDR3 1033, replacing my Phenom 9600, Asus combo - in comparison, there is no comparison. I spent hours tweaking the 9600 to run, let alone squeezing out the last MHz of power just to get it up to spec. The 995 / M4A mobo ran out of the box twice as fast as its predecessor. To say I’m please would be a gross understatement…

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User Reviews / Comments  AMD Phenom II X4 955 Black Edition

  • leeory



    "I just love beause it makes me
    yappy. Wood not own anything
    else. Untill the 995."

  • Paveguts


    "I've installed the 995 in an Asus M4A78T-e w/ 8 gb of Corsair DDR3 1033, replacing my Phenom 9600, Asus combo - in comparison, there is no comparison. I spent hours tweaking the 9600 to run, let a..."

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