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AMD Phenom II X4 955 Black Edition review




Our Score:


When AMD released its first socket AM3 Phenom processors back in February I commented that it was likely AMD had been holding back on a flagship mega-fast AM3 quad core so as not to rain on the socket AM2+ 940 Black Edition, a CPU that was only a month old but that was limited to only running on older motherboards. As such I also suggested those thinking of buying an AM3 quad core Phenom II should wait a few months for the likely arrival of a Black Edition processor. Well I hate to say I told you so, but, I told you so.

Today sees the launch of AMD's fastest CPU to date, the Phenom II X4 955 Black Edition (BE). It features a 3.2GHz default clock speed, support for both socket AM3 and AM2+ motherboards (BIOS updates permitting) and consequently is compatible with DDR2 and DDR3 memory. Its most notable feature, though, is signified by that Black Edition moniker, namely it has an unlocked multiplier that theoretically makes it very easy to overclock. Coming in at £220, it's in direct competition with Intel's Core 2 Quad Q9550, a CPU that has a markedly lower clock speed and that on the surface won't have quite the same overclocking potential.

Also announced today is the Phenom II X4 945, which runs at 3.0GHz but doesn't feature an unlocked multiplier. Understandably this means it comes in at a lower price, namely £196, though the difference seems small enough that we'd be inclined to fork out the extra for the Black Edition. We weren't provided with a sample of this CPU, though, so we've left it out of our testing.

What's immediately obvious from these prices is that AMD is still not pitching its wares as competitors to Intel's best CPUs. So if you want the best of the best it's a safe bet that an Intel Core i7 system is still the way to go. However, if you're just after a sensibly priced but still powerful system then these CPUs are likely to be prime candidates.

Given both the CPUs announced today are just faster versions of the original AM3 Phenom II CPUs we've already reviewed we won't include a full architectural breakdown of the chips. For that we refer you to our reviews of the Phenom II X4 810 and Phenom II X3 720 Black Edition and, for further information on the Phenom II architecture in general, you might also like to look at our Phenom II X4 940 review.

One last thing before we get onto testing; AMD's peculiar naming scheme. You see, when the first Phenom II CPUs launched, AMD introduced a new three-digit numbering scheme. Even at the time it didn't seem overly sensible, starting as it did at 940 - not much room for improvement there without moving to four-digits. What was even more confusing is that despite this high numbering the 940 BE was an AM2+ only chip so was almost obsolete straight away.

Since then the initial socket AM3 Phenom II chips came with an 8xx numbering because of their lower clock speeds. Meanwhile triple core AM3 processors came out with a 7xx numbering so up until this point the first digit of the model number seemed to have a clear meaning. Now, with the release of the 955 and 945, AMD has really confused things by making socket AM3 Phenom IIs with model numbers beginning in 9.

If you buy from a reputable shop, the difference between AM2+ and AM3 Phenom IIs should be made clear but we feel AMD could have made life a lot simpler by adopting a more sensible numbering system in the first place.


April 23, 2009, 7:51 pm

Looks good. FYI all the charts in your review say 810 not 955 Black Ed.


April 23, 2009, 8:05 pm

Cheers, I think they should all be fixed by now.


April 23, 2009, 9:27 pm

no conclusion!?

aww :(


April 23, 2009, 9:33 pm

You're right, we only did a 'verdict' on page 3. My bad. ;)


April 24, 2009, 1:18 am

Talk about wanting it on a plate! Overclocking used to be a bit of a black art. Soldering resistors, joining tiny bridges with conductive paint, using the right memory and tinkering with timings and voltages, fiddling with motherboard jumpers, flatting/polishing the cpu heatspreader and huge heatsink, screaming fans, all to get a few extra Mhz. I sweated blood to get a P75 running at 90Mhz on an Asus CUSL2 !

You guys get 3.8Ghz (nearly a 20% overclock) at stock voltage without lifting a finger and moan about it. How hard could it be to raise the voltage 0.1V to see if it would hit 4Ghz? Or more.

Other than that good cpu and great review ;)


April 24, 2009, 1:40 pm

As I explained, the system was essentially dead after some initial attempts and due to time constraints we weren't able to recover it for another run. Reading around, these will easily hit 3.8 on stock voltages, and are reasonably likely to reach 4 with a bit of extra voltage. Beyond that you need some serious cooling.

Nevertheless, the point I was making was that the 3.2 to 3.8 overclock we achieved was lower than the 2.8 to 3.41 we achieved with the Q9550 (both without changing any voltages) - a CPU that proved to be generally faster despite its lower clock speed. So the overclocking potential of the 955BE has to be taken with a pinch of salt.


May 16, 2009, 7:47 pm

I belive there is missclick - should be 6mb L3 cache instead of 2mb on page 1.

May i ask about cooling? Did you use components included in box or add your own cpu cooling? Was thermal paste included in box? What was temperature when oc to 3.8?

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