PhysX - Much like NVIDIA CUDA based PhysX implementation, ATI (AMD) recently announced cooperation with Intel's HAVOC engine. Though currently far less substantial, PhysX calculations over the GPU are in the work. As it works right now (example debris/cloth) physics calculations are computed over the CPU with games that support the HAVOK API. AMD is working on moving these functions to the GPU. Thus have the stream processors (shade engine) compute these functions. It's work in progress and during a recent press-briefing we asked when we can expect driver support for GPU HAVOK physics. The answer was unfortunately a bit cold. It could be a matter of months, yet also easily be the end of the year or even later. Fact remains though that the Series 4000 do support the feature and AMD considers this "work in progress" and my general feeling is that they are certainly not hasting to get it supported.
Hover with your mouse over this photo to magnify.
The product we preview today is based on the 4870, yet it has two GPUs merged together with a bridge chip utilizing crossfire technology to render your games faster. "What's Crossfire?" some of you might ask. A valid question as we take verbs like Crossfire & SLI for granted these days.
Well, just like NVIDIA's SLI, Crossfire is a situation where you add a second, third or even fourth similar generation graphics card (or in today's case GPU) to the one you already have in your PC and effectively try to double, triple, quadruple your raw rendering / gaming performance.
The idea is not new at all though .. if you are familiar with the hardware developments over the past years you'll remember that 3dfx had a very familiar concept with the Voodoo 2 graphics cards series. There are multiple ways to manage two cards rendering one frame, think of Supertiling, it's a popular form of rendering. Alternate frame Rendering, each card will render a frame (even/uneven) or Split Frame rendering, simply one GPU renders the upper or the lower part of the frame. So you see there are many methods where two or more GPUs can be utilized to bring you a gain in performance.
Today we take it even a step further. Though the X2 already has two GPUs, there's no limit to stop us combining it with yet another X2. So we will take two Radeon HD X 4870 cards, bridge them and get 4 GPUs going. So that's 4 RV770 processors running at 750 MHz. That equals 4.8 TFLOPS of performance!
Unfortunately it's also a power sucking whore in this mode, but none the less we'll look at it as well.
Well, we tried, that's for sure.
Before we dive into the photo-shoot, tests and benchmarks. Let's just compile a chart and look at the differences:
ATI Radeon HD 4850
ATI Radeon HD 4870
Radeon 4850 X2 (R700)
Radeon 4870 X2 (R700)
# of transistors
965 million x2
965 million x2
Stream Processing Units
2000 MHz GDDR3 (effective)
3600 MHz GDDR5 (effective)
2.0 GHz GDDR3 (effective)
3600 MHz GDDR5 (effective)
Math processing rate (Multiply Add)
1024MB GDDR3 x2
1024 GDDR5 x2
Power Consumption (peak)
And that last R700 product to the right we'll look at as AMD want to reveal a bit of what they are working on. Anyway, let's have a look at the product and talk some more about installation, heat, power consumption and so on.
PowerColor Radeon HD 7850 SCS3 review We test and review the PowerColor Radeon HD 7850 SCS3 today. This stock clocked Radeon HD 7850 is cooled passively, meaning it has no fans tool it down. That also means it's rather silent as it does not make any noise. But what about temperatures then you must be wondering ?
Gigabyte Radeon HD 7790 2GB OC review We test and review the Gigabyte Radeon HD 7790 2GB OC edition, also known under SKU code GV-R7790OC-2GD. We benchmark the product incl FCAT Frametimes. The new graphics card is intended to boost a little more performance into entry-level gaming. The Gigabyte HD7790 OC 2GB clocks in at 1075 MHz on the boost engine, packed with totally silent custom cooling.
MSI Radeon HD 7790 TurboDuo OC review We test and review the MSI Radeon HD 7790 OC edition, also known under SKU code R7790-1GD5-OC incl FCAT Frametimes. The new graphics card is intended to boost a little more performance into entry-level gaming.
Radeon HD 7990 review We review the new AMD Radeon HD 7990 including FCAT frametime measurements. The dual GPU product that you guys learned to know under codename Malta finally is released. AMD it doing it in style, two fully equipped Tahiti XT2 GPUs versus good yet silent cooling. In this review we'll look at the product, the architecture, the benchmarks, including frametime based FCAT measurements. Head on over towards our AMD Radeon HD 7990.