Oh NVIDIA, why. Why do you do such painful things to us gamers? Why do you over-price your cards?!?!
Fermi. A core so fantastically complex that throughout its three billion transistors, even a handful of flaws can cause drastic problems. Called GF100 internally to NVIDIA, the GTX465 uses an identical core to the top-end GTX480 card - identical in both size (529mm2) and transistor count - but in this case it comes with more than just a handful of problems. The original GF100 design calls for its processors to be marshalled into sixteen groups of 32 processors, called Streaming Multiprocessors; all GTX480 cards are flawed least with fifteen functional SMs; the GTX470 boasts fourteen; and finally, the GTX465 only manages eleven.
This means that of the potential 480 actual processors available in the current best card, the GTX480, only 352 of them are functional in the GTX465. Representing only 73 per cent of what is an already reduced core, the GTX465 also runs at the same reduced clockspeeds as the GTX470, seriously hindering potential speed. Losing some of the core has also cost some of the memory bus, resulting in only a 256-bit wide connection compared to the top-end at 384-bits. One slight benefit of this crippled core is that the Thermal Design Power, or TDP, has been lowered to 200W and shouldn't demand as much juice as other cards - though still consumes more than a 5870.
Physically the GTX465 uses the same reference cooler as the GTX470, wrapping up a complex heatsink design inside a black plastic shell. The plastic is shaped to guide cool air through the heatsink within, transferring the heat from the card's core to the air and exhausting it out the rear of the system. Formed from five direct contact heatpipes, a chunk of copper and a bunch of fins, the heatsink is a serious player, and is enough to register a serious change in operating temperatures of the card. We recorded idle temps of 37 degrees and loads of 77, down from 43 and 88 on a GTX470, while it was slightly louder at 60.5dBA and 67.0dBA respectively. Potentially ignorable at idle, but as intrusive as a rhino in labour when working hard.
Electrically the card still demands two 6-pin PCIe power connectors and a full-length PCIe 2.0 slot, offering two DVI and a mini-HDMI as output options. This particular model costs $470 as of writing, which is within spitting distance of the next step upwards. Unfortunately, the slight price drop doesn't match up in the performance stakes.
We saw underwhelming performance in Crysis, slightly choppy gameplay in GRID and a 3DMark Vantage score slower than our reference 5850 score by 484 points - and that's a benchmark heavily muddied by PhysX. Our new Heaven tests show the card is slower than the 5850 without tessellation, but if nothing else, the GTX465's dedicated tessellation units really come into play when it's been activated.
Interestingly the card had quite a lot of headroom when overclocking, which we assume is due to the heatsink. Our core clock increased by a whopping 28 per cent to 781MHz (+173) and the memory increased by 22 per cent to 978MHz (+176) for an effective quad-pumped GDDR5 speed of 3912MHz. Performance was almost that of a GTX470 at these speeds; seven extra average frames in Crysis to 35.54fps, and even 3DMark Vantage increased by 3727 points to P17999 at these clocks; a 26% performance increase for a 28% core clock increase.
So the GTX465 has the potential to be decent value, assuming the card you purchase will overclock as good as this one, but as it's not guaranteed in the slightest, an ATI 5850 makes miles more sense - and is almost $90 cheaper to boot.
Issue: 133 | February, 2012