Tom's Hardware > All Reviews > Components > Graphics Cards > GeForce GT 240: Low Power, High Performance, Sub-$100

GeForce GT 240 Specifications And Hardware

02:11 - Tuesday 17 November 2009 by Don Woligroski

Let's start with a look at the specifications of Nvidia's new GeForce GT 240-based graphics cards:

	GeForce GT 240
GPU Designation	GT215
Fabrication Process	40nm
Graphics Clock (Texture and ROP units)	550 MHz
Processor Clock (Shader Units)	1,360 MHz
Memory Clock (Clock Rate/Data Rate)	850 MHz (3,400 MHz effective) GDDR5 1,000 MHz (2,000 MHz effective) DDR3
Total Video Memory	1GB, 512MB
Memory Interface	128-bit
Total Memory Bandwidth	54.4 GB/s (GDDR5) 32.0 GB/s (DDR3)
Stream Processors	96
ROP units	8
Texture Filtering Units	32
Microsoft DirectX/Shader model	10.1/4.1
OpenGL	3.2
PhysX Ready	Yes
Video Format Support for GPU Decode Acceleration	MPEG-2, MPEG-4 Part 2 Advanced Simple Profile, H.264, VC1, WMV, DivX version 3.11 and later
HD Digital Audio over PCI Express	Yes
Connectors	DVI, VGA, HDMI
Form Factor	Single-Slot
Power Connectors	None
HDMI version	1.3a
DisplayPort	1.1
Dual Link DVI	Yes
Bus Support	PCIe 2.0
Max Board power	70 watts
GPU Thermal Threshold	105 degrees C

Just like the G 210 and GT 220 before it, the new GeForce GT 240 is based on the same GT200 architecture that spawned the GeForce GTX 200-series. We're not going to delve too deep into the GT200 architecture, since we've done that already in our GeForce GTX 280 launch article, which you can check out here.

We will go over the major specifications. however. The GeForce GTX 285 has 10 texture-processing clusters (TPCs) with 24 individual streaming processors (SPs) (or cores) in each one. Each TPC also has eight texture-management units (TMUs). There are eight 64-bit raster-operator partitions (ROPs) capable of handling eight raster operations per clock cycle each. As a result, the GTX 285 sports a total of 240 processor cores, 80 texture units, and eight ROPs capable of handling 64 pixels per clock, with all of the ROPs contributing to a 512-bit memory bus.

For comparison, the new GeForce GT 240 has four TPCs, each containing 24 SPs, for a total of 96 processor cores. Similar to the GeForce GTX 280, each TPC sports eight TMUs, for a total of 32 texture units. Two 64-bit ROPs capable of handling four pixels per clock work together to give the GPU a 128-bit memory interface and the capacity to handle eight raster operations per clock. Therefore, we expect the GT 240 to server up less than half of the processing power of a GeForce GTX 285.

The new GeForce GT 240 is also fabricated using TSMC's reportedly-problematic 40nm process, which should allow Nvidia to pull greater profit margins from this sub-$100 GPU compared to its 55 and 65nm cousins. Of course, it shares some other features with the G 210 and GT 220, such as DirectX 10.1 and Shader Model 4.1 support, eight-channel LPCM output support, and enhanced playback of DivX, VC-1, and MPEG-2 video codecs. The GeForce GT 240 is certified for not only CUDA and PhysX use, but is also GeForce 3D Vision-ready.

The biggest differentiator favoring Nvidia's GeForce GT 240 is its memory support. While the GeForce GT 220 is limited to DDR2 and GDDR3, the new GeForce GT 240 can be coupled with either DDR3 or GDDR5. This is very important, as GDDR5 offers two times the theoretical memory bandwidth per clock compared to DDR2 or GDDR3. The beauty of this is that it allows the GeForce GT 240 to offer similar memory bandwidth to GDDR3-equipped cards sporting a 256-bit memory interface (like the GeForce 9600 GT), but it keeps memory costs down. GDDR5 was one of AMD's aces when it launched the Radeon HD 4800-series cards, and this is Nvidia's first use of the technology. It's also the first time we've seen GDDR5 used on a card destined for the sub-$100 market. Nvidia's implementation of GDDR5 helps bridge the performance gap between 128-bit cards like the Radeon HD 4670 and 256-bit cards like the GeForce 9600 GT.

GeForce GT 240 distinguishes itself as the only reference card in this performance range without a dedicated power connector. This really brings the fight to the Radeon HD 4670, previously the undisputed performance king of reference cards without a PCIe power cable requirement.

Update: Wait a Minute. No SLI?

It's not all good news, however. The GeForce GT 240 lacks a feature that both the GeForce 9600 GSO and GT have offered since they were introduced: an SLI bridge connector.

Hoping that SLI might be supported over the PCI Express bus, we tried running our two test samples together. However, the driver panel wouldn't show us the option to enable SLI. Confused, we asked Nvidia for a bit of clarification. The company let us know that the GeForce GT 240 does not support SLI, and that Nvidia "typically hasn’t supported SLI for sub-$99 products, as users typically upgrade instead of buying a second card."

While Nvidia's position is certainly understandable, we find the news disappointing, as even low-end cards like the GeForce 9500 GT are often equipped with SLI support.

As far as users upgrading instead of buying a second card, Nvidia is absolutely correct: with the knowledge that the GeForce GT 240 will be replacing the GeForce 9600 GSO and GT, we had a look at Steam's Hardware Survey. According to the survey, only about 2% of gamers are running multi-GPU systems, and the GeForce 9600 GSO and GT represent about 6% of graphics cards out there. According to my math skills, that means that roughly 12 in every 10,000 gamers are running more than one GeForce 9600 in SLI.

Having said that, the GeForce GT 240 is certainly powerful enough to warrant SLI, and the lack of support for this new model is a disappointment since it is featured on the GeForce 9600-series cards being replaced.