GeForce 7800 Series
The 7800 series was designed to deliver exceptional performance and was targeted towards high-end market segment. This series has been discontinued and was replaced with the 7900 series in early 2006.
A total of 4 models were available: GeForce 7800 GTX 512, GeForce 7800 GTX, GeForce 7800 GT, and GeForce 7800 GS.[11]
- Advanced Features Support
The 7800 series supports following advanced features:
| Intellisample 4.0 Technology |
| Scalable Link Interface (SLI) Technology |
| High dynamic range rendering Technology |
| UltraShadow II Technology |
| CineFX 4.0 Engine |
| Nvidia PureVideo Technology |
GeForce 7800 GT
The GeForce 7800 GT is the second GPU in the series, launched on August 11, 2005 with immediate retail availability. It has 20 pixel pipelines, 7 vertex shaders, 16 ROPs and a 400 MHz core clock, 500 MHz memory clock (1 GHz effective) using GDDR3 memory.
The GeForce 7800 GT had been introduced as a more affordable alternative to the 7800 GTX. At the time it was considered the performance/cost champion of video cards.
GeForce 7800 GS AGP
On February 2, 2006, Nvidia announced the 7800 GS as the first AGP video card in the GeForce 7 series lineup, an AGP version of the high-end GeForce 7 Series.[12]
This card was promoted by several hardware enthusiasts as "the last high-ended AGP card in existence". It has 16 pixel shader units instead of the 20 that the 7800 GT has, but still benefits from the optimizations of the other 7-series GPUs enjoy. Clock speeds are 375 MHz for the GPU and 1200 MHz for the (GDDR3) memory. According to all benchmark tests, the performance of this card is faster than the GeForce 6800 GT and GeForce 6800 Ultra. Different vendors may deviate from the stated specification. It serves to provide a great upgrade path for those with high-end AGP systems who don't want to switch to a new high-end PCI-Express system.[13] There was a special "Golden Sample" release from Gainward that was called "7800 GS+" or officially "Bliss 7800 GS 512 MB GS+" that had default clock speeds of 450 MHz core and 1250 MHz memory. Unlike a standard 7800 GS, the 7800 GS+ actually used a 7900 GT GPU that had the full 24 pixel shaders instead of the regular 16 pixel shaders that are normally found on a 7800 GS video card.
Gainward had previously released a "Bliss 7800 GS 512MB GS" card that was based on a 7800 GT but utilized the AGP bus. Its external appearance and name make it nearly indistinguishable from the 7900 GT-based Bliss 7800 GS 512MB GS+. Leadtek produced a similar card with 256MB memory.
In late 2006 Gainward released a third '7800 GS' card with 20 pixel shaders running at 500 MHz core and 1400 MHz memory called the "BLISS GS-GLH". This card is also based on the 7900 GS core.
There are no after-market cooling systems for the 7800 GS, stock cooling in the GeForce 7800 GS AGP is adequate. The board layout is radically different from other GeForce 7 boards so no universal aftermarket coolers would fit without significant modification to their mounting mechanisms.
GeForce 7800 GTX
The GeForce 7800 GTX (codenamed G70, and previously NV47) was the first GPU in the series, launched on June 22, 2005 with immediate retail availability. The GeForce 7800 GTX supported the highest specification DirectX 9 vertex and pixel shaders, at the time: Version 3.0. It was natively a PCI Express chip. SLI support had been retained and improved from the previous generation.
According to PC World, the 7800 GTX was "one of the most complex processors ever designed". The GPU had 302 million transistors (the Athlon 64 X2 4800+ CPU has 233.2 million transistors), along with 24 pixel and 8 vertex shaders.[14] This card included new standard features, such as subsurface scattering[citation needed], HDR lighting, and radiosity[citation needed], to name a few. It was succeeded by the 7900 GTX on March 9, 2006.
Here is how the released versions of the "GeForce 7" series family compare to Nvidia's previous flagship GPU, the GeForce 6800 Ultra, and ATI's Radeon X1800 XT:
| GeForce 6800 Ultra | GeForce 7300 GS | GeForce 7600 GT | GeForce 7800 GTX | GeForce 7900 GTX | Geforce 7950 GX2 | ATI Radeon X1800 XT | ATI Radeon X1900 XTX | |
|---|---|---|---|---|---|---|---|---|
| Transistor count | 222 million | 112 million | 178 million | 302 million | 278 million | 2 * 278 Million | 321 million | 384 million |
| Manufacturing process | 130 nm | 90 nm | 90 nm | 110 nm | 90 nm | 90 nm | 90 nm | 90 nm |
| Die Area | 288 mm² | 77 mm² | 125 mm² | 333 mm² | 196 mm² | 2 * 196 mm² | 288 mm² | 352 mm² |
| Core clock speed | 400 MHz | 550 MHz | 560 MHz | 430 MHz | 650 MHz | 500 MHz | 625 MHz | 650 MHz |
| Number of Pixel Shader units | 16 | 4 | 12 | 24 | 24 | 48 | 16 | 48 |
| MADD ALUs per PS unit | 1 | 2 | 2 | 2 | 2 | 2 | 1 | 1 |
| Number of ROPs | 16 | 2 | 8 | 16 | 16 | 32 | 16 | 16 |
| Number of TMUs | 16 | 4 | 12 | 24 | 24 | 48 | 16 | 16 |
| Number of vertex pipelines | 6 | 3 | 5 | 8 | 8 | 16 | 8 | 8 |
| Peak pixel fill rate (theoretical) | 6.4 Gigapixel/s | 1.1 Gigapixel/s | 4.48 Gigapixel/s | 6.88 Gigapixel/s | 10.4 Gigapixel/s | 16.0 Gigapixel/s | 10.0 Gigapixel/s | 10.4 Gigapixel/s |
| Peak texture fill-rate (theoretical) | 6.4 Gigatexel/s | 2.2 Gigatexel/s | 6.72 Gigatexel/s | 10.32 Gigatexel/s | 15.6 Gigatexel/s | 24.0 Gigatexel/s | 10.0 Gigatexel/s | 10.4 Gigatexel/s |
| On-board memory interface | 256 (4*64-bit) | 64 (1*64-bit) | 128 (2*64-bit) | 256 (4*64-bit) | 256 (4*64-bit) | 2 * 256(4*64-bit) | 256 (8*32-bit) | 256 (8*32-bit) |
| Memory clock speed | 1.1 GHz GDDR3 | 810 MHz DDR2 | 1.4 GHz GDDR3 | 1.2 GHz GDDR3 | 1.6 GHz GDDR3 | 1.2 GHz GDDR3 | 1.5 GHz GDDR3 | 1.55 GHz GDDR3 |
| Peak memory bandwidth | 35.2 GB/s | 6.5 GB/s | 22.4 GB/s | 38.4 GB/s | 51.2 GB/s | 76.8 GB/s | 48.0 GB/s | 49.6 GB/s |
| Power Consumption Idle [15] | ? Watts | 8.7 Watts | 14.6 Watts | 29 Watts | 31 Watts | ? Watts | 30.2 Watts | 29.5 Watts |
| Power Consumption Peak 2D | ? Watts | 10.3 Watts | 22.5 Watts | 52 Watts | 52 Watts | ? Watts | 52.1 Watts | 50.1 Watts |
| Power Consumption Peak 3D | ? Watts | 16.1 Watts | 35.8 Watts | 81 Watts | 84 Watts | 110 Watts | 103.1 Watts | 120.7 Watts |
GeForce 7800 GTX 512
The 512 MB version of the GeForce 7800 GTX was released on November 14, 2005. The card features more than simply an increased frame buffer from 256 MB to 512 MB. The card features a much improved core clock speed of 550 MHz vs. 430 MHz (27.9% increase) and fast 1.1 ns GDDR3 memory clocked at 1.7 GHz vs. 1.2 GHz (41.7% increase), when compared to the original version. Like ATI's X1800 XT, the addition of another 256 MB of memory, and to a lesser extent, the increased clock speeds, have raised the heat and power output significantly. To combat this, the GeForce 7800 GTX 512 sports a much larger yet quieter dual slot cooling solution when compared to the original 256 MB version.[16]
- Performance Specs
- Core Clock Speed: 550 MHz
- Memory Interface: 256-bit
- Memory Bandwidth: 54.4 GB/s memory bandwidth
- Fill Rate: 13.2 billion pixel/s
- Vertex/s: 1100 million
- Shader Power: 24 pixels per clock
- Memory Type: GDDR3
0 comments:
Post a Comment