Review: AMD FX 6100 Black Edition

Overview

When is a six-core PC processor not a six-core PC processor? When it's AMD's new FX 6100 Black Edition.

Long before AMD released its fancy new FX chips, we had a feeling a fisticuffs was brewing over the definition of what constitutes a processor core.

Now the FX has arrived and the gloves are off.

It all comes down to the radical new approach to simultaneous multi-threading (SMT) taken by AMD with the new Bulldozer architecture.

Intel's been doing SMT for a bit in the form of Hyper-Threading and fair to say Chipzilla's take can be called SMT lite.

It hasn't spent a lot of transistors in enabling each of its processors cores tow run two software threads in parallel. So a multi-threading performance boost of around 15 to 20 per cent is a pretty decent outcome.

AMD reckoned it could do better and verily cooked up the Bulldozer module. This little techno-beasty packs a pair of execution units. But much of what you'd normally consider a processor core is shared.

So has that Bulldozer module got enough power to give this six core processor a chance?

Benchmarks

The very least you'd hope from this latest 'six-core' processor from AMD is that it would beat the previous generation of hex core chips, here represented by the AMD Phenom II X6 1100T.

Sadly it's well off the pace the previous generation sets.

Most tragic of all is just how weak it is in gaming terms. The older processor has it licked.

3D Rendering performance

Video encoding performance

CPU gaming performance

Verdict

On paper it's hard to say whether a Bulldozer module it one hell of a single-core solution or truly deserves to be counted as two cores.

In practice, however, it's all too clear.

A single Bulldozer module doesn't deserve dual-core status. For proof, observe how this triple-module, supposedly six-core, AMD FX 6100 Black Edition chip compares with AMD's own Phenom II X6 1100T.

That's a true six-core chip and one that isn't exactly famed for world-beating per-core performance. Put simply, the 1100T owns and it owns in every metric save memory bandwidth.

As if that wasn't enough, comparisons with Intel's quad-core chips make the AMD FX 6100's six-core status look even sillier.

The non Hyper-Threaded Core i5-2500K mugs it in every test. Meanwhile, the Core i7-2700K is in another league.

What's more, in terms of overclocking, having one less active module compared to the FX 8150 doesn't appear to deliver much benefit. We didn't get significantly higher clocks out of the 6100.

If that makes the AMD FX 6100 sound pointless, it's not quite as bad as that.

AMD has priced it keenly. At £128, you can make an argument for it as a cheap multi-threading chip. The allure becomes even greater when you factor in the possibility that you might be able to flick a BIOS switch and enable that hidden Bulldozer module.

The same applies doubly to the dual-module FX 4100. However, there are absolutely no guarantees and it will take a few months and a bit of forum trawling before we have a feel for how successful FX buyers are finding their module-unlocking exploits.

Until then, we'll put a hold recommendation the AMD FX 6100 Black Edition.

At stock clocks and with the final module hidden, it's not terribly exciting. However, if it turns out that most of all 6100s will happily run with the final module enabled, it might just be worth a roll of the dice.

If that happens, we'll be more than happy to upgrade the 6100's status to buy.

We liked:

In multi-threaded terms the AMD FX 6100's performance isn't bad, still lagging behind the previous top hex core CPU from AMD.

We disliked:

Again it's the weak single-core performance of the Bulldozer architecture that makes for one massive technological sad-face.

We'd like to say positive things about the possibility of unlocking those dormant cores, sadly though we simply can't say how likely it is to happen.

Final word:

An interesting option, but only if the module-enabling prospects turn out good.

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