Following hot on the heels of the R9 280X is another chip with the 'X' after its name - the R9 270X. It's also a member of the R9 family, and while this series is really designed for enthusiasts, the range is fairly wide - from the most powerful AMDs right down to this highly affordable £170 270X. Like the 280X, this product is a twist on the older AMD technology, rather than supplying completely new architecture. It's primarily a 7870 with better clock speeds. Both the 270X and the 7870 chips offer the same core clock of 1GHz, but the the 270X adds a Boost clock that pushes it up an extra 50MHz to a potential 1050MHz. In the case of this MSI overclocked version, that core clock (from a standard 1030MHz) has been given a further jolt, knocking it up to 1120MHz. It sticks to the factory settings when it comes to the memory clock, but even the default 270X gets a decent jump from the 7870 in any case - elevated from 1.2GHz (4.8GHz DDR effective) to 1.4GHz (5.6GHz DDR effective). (See all graphics card reviews.)
In many other respects, the 270X is pretty much identical to the 7870. So both have 80 texture units, for instance, and 1280 stream processors. All of this means that the 270X has some very decent bandwidth and texture fill rates. The latter figure, 89.6GTps, is a good 9.6GTps ahead of the 7870, and only around 13.3GTps behind the impressive 280X. Both the 270X and 7870 have 256bit memory interfaces, but the 270X's superior clock rates help it to a memory bandwidth rate of 179.2GBps - a good 25.6GBps ahead of that 7870. It has to be said that the 280X, with its 384bit memory interface, remains a long way ahead here, on 288GBps. Nonetheless, the 270X has some impeccable rates for a £170 card. (See also Group test: what's the best graphics card?)
The chip does only come with 2GB of memory, which may see it struggling two years from now. A £170 card is unlikely to be a long-term purchase, but it is worth bearing in mind if you're debating whether to lay down the extra for the 280X. 4GB versions of the 270X are likely to be launched, but the extra memory will add considerably to the price, while still not allowing the card to compete fully with its bigger brother. There is also some competition to the 270X in terms of the 270. This lower-clocked version is broadly similar, but offers a core clock of only 900MHz (with a Boost to 925MHz). The memory clock speeds are identical, though, as are most of the other specifications. At the time of writing, the difference between these cards amounted to little more than £15-£20, which would seem to point to the 270X as having a distinct advantage. If the gap widens, we may cover the 270 separately.
The best way to make a chip work more efficiently is to improve the architecture. However, since the 270X is making use of older technology, this clearly isn't an option. As such, the raising of the clock rates means that the 270X needs more power to operate - it requires two 6pin power connectors from the PSU. The chip's TDP is 150W, although we were seeing typical power consumption some 15 watts higher than this. The 7870, by contrast, gets closer to the 140W mark in realworld testing, despite having a TDP that's supposedly higher than the 270X's. The 270X is certainly a lot more power efficient than the 280X, but we will need to see a new design before AMD can resume the trend of falling power output rates. The MSI is a fairly quiet card, even if marginally louder than the wonderfully discreet 280X that we tested. Overall, though, we had no problems with the sound levels.
On raw performance, the R9 270X isn't as inferior to the 280X as you might expect. In Crysis 3, the 270X's figures of 32.8 and 21.7fps (at resolutions of 1920x1080 and 2560x1440 respectively) compare reasonably favourably with the 280X's 39.8 and 22.1fps. Particularly at the higher resolution, the difference is very small. As the detail levels tumble, the 280X stretches away, but the 270X's performance is still very palatable. In Bioshock, it also holds on to the 280X well, notching up figures of 64.4 and 38.9fps, as against the 280X's equivalents of 70.8 and 44.5fps. Only in Stalker: Call of Pripyat did the R280X start to work its way into the distance, and its figures of 94.7 and 70.3fps were very much superior to the 270X's of 80.1 and 62.3fps. This widening gap could, again, be because the 280X exerts more power over the 270X when detail levels are lower. The 7870 was inferior to the 270X all along. In Stalker, for instance, its figures of 71.3 and 49.5fps were a significant distance behind the 270X's.