Nvidia GeForce GTX Titan 6GB review
Matthew takes a look at Nvidia's new monolithic GPU, the Titan
The next major graphics card launches from Nvidia and AMD are both still a long way off, so the new GTX Titan 6GB from Nvidia is interesting in that it enters the market as the green team's top-end single GPU card, but at a price equivalent to that of its dual GPU monster, the GTX 690 4GB. On the price to performance scale, then, it's unlikely to be a success, but arguably when you're forking out over £800 on a graphics card, value for money isn't quite as important as it is for more sensibly priced products.
The GTX Titan is essentially the desktop edition of Nvidia's enterprise Tesla GPU that's found in supercomputers around the world, although the GPU isn't exactly the same. The current high-end 600-series cards are based on the GK104 GPU, a 28nm revision of the GF114 GPU found in the GTX 560 Ti from last generation. The new Titan, however, utilises the GK110 GPU, the 28nm version of the GTX 580 1.5GB's GF110 GPU. It's therefore basically a demonstration of what Nvidia's Kepler architecture can really do.
The Kepler architecture is based on graphics processing clusters (GPCs) divided into streaming-multiprocessors (SMs) that consist of 192 stream processors and 16 texture units each. Nvidia's previous top-end single GPU card, the GTX 680 2GB, has four GPCs with two SMs each. The Titan, however, has five GPCs, each of which houses three SMs, although one of these on the chip is disabled, leaving a total of 14. The end result is a card with 2,688 stream processors (a 75% boost over the GTX 680 2GB) and 224 texture units.
The GPU has access to a whopping 6GB of GDDR5 memory via six 64-bit memory controllers. With the memory clocked to 6GHz effective, this gives the card a massive memory bandwidth of 288GB/s, so the Titan really is a powerhouse. The GPU chip itself is clocked at a fairly modest 836MHz with a guaranteed boost clock of 876MHz, but in practice it will boost to almost 1GHz without any manual overclocking.
The dual slot card measures 267mm in length. It takes in power through a six-pin and an eight-pin PCIe power connection and has a TDP of 250W (higher than the GTX 680 2GB and lower than the GTX 690 4GB). Its aluminium casing makes the card really quite attractive. A single radial fan draws air in, cooling the small power circuitry heatsink as well as the main aluminium fin stack, which sits above a vapour chamber. The memory chips on the rear of the PCB are left exposed and without anything to cool them.
The rear I/O panels consists of a pair of DVI ports, a single HDMI connection and a DisplayPort output, so most setups should be catered for. There are also a pair of SLI connections on each Titan card, so you could in theory connect up to four together in a single system if you were rich and crazy enough to do so.
In performance terms, Nvidia's Titan is by far and away the fastest single GPU card available, as it leaves both the GTX 680 2GB and AMD Radeon HD 7970 3GB GHz Edition in the dust. It can handle three screen gaming at maximum settings in games like Battlefield 3, The Witcher 2 and even Crysis 3 (without anti-aliasing). The multi-GPU GTX 690 4GB, which costs around the same, does tend to outperform it, but not always, because even though it has more powerful hardware to hand, it's heavily reliant on optimised drivers to make the most of it.
I was able to overclock the card to a 980MHz core clock and 6.6GHz memory clock - gains of 12 and 10% respectively. At these settings, the card actually boosted to 1,123MHz when under load, which is a huge increase. It still wasn't enough for the card to catch up to the GTX 690 4GB, but nevertheless improvements in frame rates were still evident.
If you're lucky enough to be able to splash out over £800 on graphics hardware, multi-GPU cards like the GTX 690 4GB or CrossFire and SLI setups inevitably have the ability to outperform the GTX Titan. Such setups do come with issues of stability and increased power draw, but driver optimisations are continuing to improve. Nevertheless, the GTX Titan is consistently fast, which can't be said of all multi-GPU setups, and is less frustrating as a result. It's an awesome piece of kit without doubt, so it really comes down to what you're most willing to live with.
• Price: £839.75
• Manufacturer: Nvidia
• Website: www.nvidia.co.uk
• Required spec: One free PCIe expansion slot, 1 8-pin and 1 6-pin PCIe power connectors