| nVidia
SLI Ready Video Cards |
Would you like to
experience the amazing power of two high-end video cards directly linked
and working together as a single card?  Now,
NVIDIA unveils a revolutionary approach to combining multiple GPUs in a
single system to scale performance. NVIDIA® SLI™ (Scalable
Link Interface) multi-GPU technology takes advantage of the increased
bandwidth of the PCI Express™ bus architecture, and features intelligent
hardware and software solutions that allow multiple GPUs to efficiently
work together to deliver high performance graphics display on one monitor.
Every high-end PCI Express reference board
from NVIDIA will support SLI. The current products that has support for
SLI are the GeForce 6800Ultra, GeForce 6800 GT, GeForce 6600 GT, and
NVIDIA Quadro FX 3400.
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| The new NVIDIA SLI
video card has advanced compositing, rendering, and scan out technology
delivers uncompromised image quality, eliminating the “flashing”
effect found in previous solutions. NVIDIA SLI multi-GPU technology also
supports both analog and digital output. An intelligent
communication protocol embedded in the GPU, and a high-speed digital
interface, NVIDIA SLI-based GPUs can easily communicate with one another
without the overhead associated with a bus. In addition, a unique software
algorithm efficiently shares the workload to deliver extraordinary picture
performance. |
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| Each card renders
half of the image scan lines which results in double the performance of a
single board and the ability to play OpenGL games. To date no
manufacturer has come up with a similar concept simply because modern
graphics accelerators are all AGP based, there's no dual AGP motherboards
and PCI simply doesn't have the bandwidth to handle modern graphics
accelerators. |
Both
6600 and 6800 series PCI-E cards are connected by means of a SLI, Scalable
Link Interface, dubbed the MIO port, a high-speed digital interconnect
which connects to a connector on top of both cards. This connector is
actually available on all PCI-E GeForce 6800 series graphics cards.
Through this MIO port both cards communicate to each other and distribute
the workload which is accelerated by dynamic load-balancing algorithms. The
screen is divided vertically in two parts; one graphics card renders the
upper section and the second graphics card renders the lower section.
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The load balancing algorithms distribute
the load across the graphics processors. Initially they'll both start out
at 50% but this ratio can change depending on the load. Although Nvidia
has remained tight-lipped about what makes their SLI implementation tick
exactly it is clear that both hardware and software contribute to making
SLI work. Most of the dynamic load balancing between the two graphics
processors is handled in software and the SLI needs driver support.
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| Nvidia has told us
that prospective performance numbers should show a performance increase
closer to 90% over that of a single graphics card. There are a few things
that need to be taken into account however when you're considering buying
an SLI configuration. First off you'll need a workstation motherboards
featuring two PCI-E-x16 slots which will also use the more expensive Intel
Xeon processors. Secondly you'll need two identical, same brand and type,
PCI-E GeForce 6800 graphics or GeForce 6600 graphics cards. |
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| For workstation
users the SLI configuration has a total of four DVI connector so it can
display on four monitors and it can be driven off of the respective DVI
outputs on the graphics cards. The feature we'll undoubtedly see pitched
as a major feature for the Quadro FX version of the GeForce 6800 series
SLI configuration. Fortunately they do not require dual Xeons, a single
Xeon will work just as well. All in all Nvidia's SLI implementation brings
back fond memories of the 3dfx cards days and has all the right
ingredients to once again revolutionize 3D graphics provided you're
willing and able to pay the hefty price tag associated with it. Nvidia for
once again raising the bar and making the harts of many gamers rejoice.
The new SLI is here and it looks even better then the 3DFX graphics cards. |
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NVIDIA
SLI Ready
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GeForce
6800 Ultra |
GeForce
6800 GT |
GeForce
6800 non-Ultra |
GeForce
6600 GT |
GeForce
6600 |
| Transistor
count |
222
million |
222
million |
160
million |
146
million |
146
million |
| Manufacturing
process |
0.13-micron |
0.13-micron,
low-k dielectric |
0.13-micron |
0.11-micron |
0.11-micron |
| Core
clock speed |
400MHz |
350MHz |
325MHz |
500MHz |
300MHz |
| Number of
pixel pipes |
16 |
16 |
12 |
8 |
8 |
| Number of
texturing units |
16 |
16 |
12 |
8 |
8 |
| Number of
vertex processors |
6 |
6 |
6 |
3 |
3 |
| Peak
pixel fill rate (theoretical) |
6.4Gpixels/sec |
5.6Gpixels/sec |
3.9Gpixels/sec |
4Gpixels/sec |
2.4Gpixels/sec |
| Peak
texture fill rate (theoretical) |
6.4Gpixels/sec |
5.6Gpixels/sec |
3.9Gtexels/sec |
4Gtexels/sec |
2.4Gpixels/sec |
| Memory
interface |
256-bit |
256-bit |
256-bit |
128-bit |
128-bit |
| Memory
clock speed |
1.1GHz
DDR-3 |
1GHz
DDR-3 |
700MHz
DDR-2 |
1GHz
DDR-3 |
TBD
by board maker, DDR-1 |
| Peak
memory bandwidth |
35.2GB/sec |
32GB/sec |
22.4GB/sec |
16GB/sec |
Varies
with memory clock speed |
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NVIDIA
SLI Ready |
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| ASI
SKU |
Model |
Manufacture |
NVIDIA
SLI Ready |
| 30912 |
Quadro
FX3400 PCI-E 256MB RETAIL |
PNY
Click
here for link |
YES |
| 30913 |
Quadro
FX3400 PCI-E 256MB BULK |
PNY
Click
here for link |
YES |
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| With the new
arrival of PCI-E things have changed. A number of workstations
motherboards featuring the Tumwater chipset will have dual PCI-E-x16 slots
making dual graphics accelerators a possibility again. Nvidia steps up to
the plate today with the re-introduction of the SLI concept on the GeForce
6800 series, again using the SLI moniker but now with a different approach
to the same principles that made Voodoo2 SLI a huge success.
NVIDIA SLI-Ready Motherboard:
Supports a PCI Express chipset and includes two physical connectors for
two NVIDIA PCI Express graphics cards.
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