It's been an interminably long time coming, but Nvidia has finally launched the sub-£200 graphics based on its new Kepler chip architecture. Today's announcement sees a brace of polygon pushers out from the GPU giant, namely the GeForce GTX 660 and GeForce GTX 650. Priced respectively at £179/$229 and £89/$159 – and UK prices include VAT – they fill a gaping hole in

The GTX 660 especially could be one of the most popular cards in recent memory, if it performs well. Let's take a look at what inside, shall we?

GTX 660 is a completely new chip for Nvidia, codenamed GK106 and formed of five Kepler 'SMX' units. Individually, these are identical to the SMXs found on other six series chips, with 192 execution cores a piece, 16 texture units and so on. The total configuration for the chip, then, is a hefty 960 cores, 80 texture units and 24 ROPS.

There's also 2GB of GDDR5 memory running over a 192bit interface.

GTX 660 uses the whole GK106 chip, we're told, which means that there's scope for Nvidia to do a cut down 550Ti or 555 in the future.

Clockspeeds will vary depending on manufacturer, and so far Kepler has proved itself very capable of overclocking, but a stock GTX 660 will run at 980MHz, and make use of Nvidia's Boost technology to speed itself up to 1053MHz as an when the thermal envelope allows. Memory runs at the equivalent of 6008MHz by default.

It's a solid looking card, which doesn't sacrifice too much power from the recently released 660Ti . Nvidia is claiming that it will be between 5% and 44% faster than an equivalently priced Radeon HD7850. Power usage stats are – like the rest of the Kepler line-up – good too. The maximum TDP is 128W, which compares to 150W for a GeForce GTX 560, and we know from other tests that Kepler throttles back well when not running flat out.

The GeForce GTX 650 is around half the price of the 660, but a far less interesting chip from our perspective since it's essentially just an overclocked GTX 640 using an identical GK107 chip with 384 execution cores.

The question is, of course, how do the two new cards perform? I've not had my hands on one to test yet, but here's what the web thinks:

Anandtech says there's no surprises, but puts the GTX 660 slightly ahead of AMD's HD7870 (give or take). It's not worth upgrading from a 560Ti, but "unquestionably a meaningful upgrade to an aging Fermi card"

Bit-tech believes it's "the mid range card of choice" now - which again is what we were mostly expecting.

Tweaktown has had its hands on an overclocked version from MSI, which it likes a fair bit.

Hexus , meanwhile, thinks Nvidia could have done it cheaper, but finds the 660 as fast as last year's flagship GTX 580 - so all good there then.

In other words, it's looking good and disappointing only in that it doesn't exceed expectations, rather than meeting them. We'll be playing around with one in the office this week, but it's looking very likely to be a shoe in for the PC Gamer Rig.