NVIDIA GeForce GTX 275

GeForce GTX 200 Series Comparison
	GeForce GTX 285	GeForce GTX 280	GeForce GTX 275	GeForce GTX 260 (revised 216 shader)
Manufacturing Process	55-nm	65-nm	55-nm	55-nm
Core Graphics Clock Speed	648MHz	602MHz	633MHz	576MHz
Stream Processor Clock	1,476MHz	1,296MHz	1,404MHz	1,242MHz
# of Stream Processors	240	240	240	216
Memory Clock Speed	1,242MHz (2,484MHz effective)	1,107MHz (2,214MHz effective)	1134MHz (2268MHz effective)	999MHz (1,998MHz effective)
Memory Interface	512-bit	512-bit	448-bit	448-bit
Memory Bandwidth	159GB/sec	141.7GB/sec	127GB/sec	111.9GB/sec
Memory Size	1GB	1GB	896MB	896MB
ROPs	32	32	28	28
Texture Filtering Units	80	80	80	72
Texture Filtering Rate	51.8Gigatexels/sec	48.2Gigatexels/sec	50.6 GigaTexels/sec	41.5 Gigatexels/sec
Display Connectors	2xDual-link DVI 1xHDTV-out	2xDual-link DVI 1xHDTV-out	2xDual-link DVI 1xHDTV-out	2xDual-link DVI 1xHDTV-out
Power Connectors	2x6-pin	2x6-pin	2x6-pin	2x6-pin
Max Board Power	183 Watts	236 Watts	219W	182 Watts
HDMI	Yes, Via Adaptor	Yes, Via Adaptor	Yes, Via Adaptor	Yes, Via Adaptor
Audio Input for HDMI	SPDIF passthrough	SPDIF passthrough	SPDIF passthrough	SPDIF passthrough

Based on the exact same GT200b GPU used in the GTX 285 and 55-nm GTX 260 launched earlier this year, the GeForce GTX 275 is a bit of a hybrid of sorts in the sense that it features the full 240-shader architecture found in the GTX 280 and GTX 285, yet it retains the 448-bit memory interface used on the GTX 260, with 896MB of memory onboard.

To further separate the GeForce GTX 275 from the GTX 260, NVIDIA also cranks up the clocks rather significantly, as the GTX 275 runs at 633MHz – just 15MHz shy of the flagship GTX 285 – while the stream processors are clocked at 1,404MHz. These speeds are significantly higher than the GTX 260, and even the GTX 280, which was once NVIDIA’s most powerful GPU.

The GeForce GTX 280 eclipses the GTX 275 in only one category: its memory subsystem. While it runs at slower clocks, thanks to one additional 64-bit memory controller, the GTX 280 boasts a 512-bit memory interface with 1GB of memory. This gives the GTX 280 a slightly larger frame buffer and memory bandwidth advantage, but the GTX 275’s texture filtering advantage gives it the edge in cases where the memory subsystem doesn’t come into play.

As you’ll see in our benchmarks, the GTX 275 and GTX 280 run neck-and-neck with each other for the most part, so essentially with the GeForce GTX 275 NVIDIA’s giving you GTX 280 performance at a new lower price point of $249 before rebates.


The GTX 275 board itself is based on the same design and cooling used for other GT200b GPUs. We’ve found that while it gets the job done adequately enough, due to compromises that have been made in the cooling to cut costs, we don’t see the temp reductions we expected out of a smaller, less power hungry 55-nm chip. Load temps are at best on par with, and usually a little higher than their 65-nm counterparts.

Fortunately NVIDIA’s GT200 GPUs were never known for running hot (at least in comparison to RV770), but if you were expecting a cooler-running alternative to the GTX 280 and GTX 260, you’ll likely be a little disappointed. We have found that GT200b GPUs tend to cool down significantly faster than GT200 when going from load down to idle though.

The GeForce GTX 275 is expected to sell for an MSRP of $249, with boards hitting retail in some regions by the end of today, and worldwide retail availability expected by April 14th.

Ambient occlusion

Besides the new graphics card, another new feature NVIDIA is launching today is the addition of ambient occlusion in their ForceWare 185 release driver. The feature is enabled via application profiles, with the ForceWare 185 driver currently capable of supporting ambient occlusion in 22 games:

Assassin's Creed

BioShock

Call of Duty 4

Call of Duty 5

Call Of Juarez

Company Of Heroes

Counter-Strike Source

Dead Space

Devil May Cry 4

F.E.A.R. 2

Fallout 3

Farcry 2

Half Life 2 series

Left 4 Dead

Lost Planet: Colonies

Lost Planet: Extreme Condition

Mirror's Edge

Portal

Team Fortress 2

Unreal Tournament 3

World In Conflict

World of Warcraft

(Note: STALKER: Clear Sky and Crysis natively support ambient occlusion in the game’s graphics menu options)

As of right now the feature is unique to D3D titles, with no plans to add OpenGL support at the moment. The feature looks better in some games than others, with the aforementioned titles in bold delivering the most distinctive improvement visually according to NVIDIA. The neat thing about it is that it’s a feature that can be used to enhance older titles such as those based on the HL2 engine, which already run at blazing frame rates anyway (the performance hit generally ranges from 20-40% according to NVIDIA). NVIDIA provided us with the following before/after screenshots:

Company of Heroes AO off

Company of Heroes AO on

World in Conflict AO off

World in Conflict AO on

Mirrors Edge AO off

Mirrors Edge AO on

Half-Life 2 AO off

Half-Life 2 AO on