As with the GTX 660 Ti, almost all of NVIDIA's add-in partners are expected to produce their own custom version of this card, and in many cases, you can expect multiple versions of differing specifications and price. We've managed to get our hands on three of the earliest to launch custom models from the big three of PC components: ASUS, Gigabyte and MSI. Others like Palit, Galaxy and Zotac will follow and we'll bring you coverage of those in the near future.
As with ASUS' GTX 660 Ti, ASUS once again holds the distinction of having the highest overclocked GTX 660, with its DirectCU II TOP model raised from 980MHz all the way up to 1072MHz. Memory speeds have also been given a small boost, up to 6108MHz DDR. Like most of ASUS' custom cards, it uses the popular dual-fan DirectCU II cooling system. This particular model utilizes three nickel-plated copper heatsink pipes in direct contact with the GPU, connected to an array of cooling fins, and ventilated by two fans.
ASUS actually makes three variants of the GTX 660 Direct CU II. The TOP model we're reviewing retails for S$409. For S$10 less, a DirectCU II OC edition, which has a lower core overclock of 1020MHz, but is otherwise identical, retails for S$399, while the non-OC DirectCU II version which uses default clock speeds, sells for S$390. All versions come with a 3-year replacement warranty period.
Gigabyte's GeForce GTX 660 has been overclocked to 1033MHz on the core, with memory remaining at the default 6008MHz DDR.
Gigabyte's model uses the same 'open design' as its GTX 660 Ti, with a very minimal fan shroud. A good fan shroud is usually designed to improve air flow direction, however, it may not always be necessary and, in fact, combined with good chassis air flow, GPU temperatures may actually be lower without one. Additionally, Gigabyte's model compensates somewhat by using 100mm fans, much larger than our other two custom models. We'll find out later in the review if this design helped it garner better operating temperatures.
Under the fans, four 6mm copper heatpipes are connected to two heatsinks, one directly over the GPU, and one elevated to the side.
This model retails for a very affordable S$345 and is issued with a 3-year warranty period.
MSI's GeForce GTX 660 is very similar in spec to Gigabyte's, with core clock speeds ramped up to the same 1033MHz and memory remaining at the default 6008MHz DDR. This model uses MSI's Twin Frozr III cooler, consisting of three large, nickel-plated, copper heatpipes and a large cooling fin array connected to two heatsinks, one heatsink directly over the GPU and another that covers the memory chip and voltage regulation circuitry. Two 'propeller fans', so named for their tight 13-blade array, and designed for increased airflow, keep everything ventilated.
The MSI GeForce GTX 660 Twin Frozr III OC retails for S$389 and comes with a three-year warranty.