What can you get for a hundred bucks these days? - ATI introduces the Radeon 4770
Posted by Robert Dow and Alex Garovi on April 28th 2009 | Discuss
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A damn powerful graphics AIB—ATI introduces the Radeon 4770
Resistance is futile – you will buy a new AIB
We test a lot of things here at Mt. Tiburon Testing labs, mostly stuff that has a pixel associated with it, and sometimes things that just amuse or interest us.
Last year, we became concerned with the narrow focus in evaluating graphics add-in boards (AIBs) and felt the emphasis on just the highest 3DMark Vantage score or the highest frames per second (FPS) score (using Fraps) in a game was not helping the consumer, or the manufacturers of AIBs understand the total picture or value of the AIB.
The Pmark
We also think the consumer has changed and is not only looking for more value but demanding it. And so, in a recent blog Jon proposed a three parameter test which we have named the “Pmark.”
Where:
- Performance is expressed in 3DMark Vantage score
- Price is expressed in US dollars
- Power is expressed in watts of the AIB
When Performance is expressed in FPS then the FPS score is multiplied by 100 to put it in the same range as the 3D Vantage scores.
It must be pointed out that this analysis wasn’t done to prove one company’s product is superior to another but rather to arrive at a better metric for evaluating products for the mainstream consumers.
Be careful of gaming
This doesn’t mean one should omit the base analysis in forming a buying decision. You can, for instance, imagine a product that has a horrible benchmark score but is ridiculously cheap and doesn’t use any power. That product would win, but it would most likely be terribly disappointing.
A point in time
Benchmarks are temporal. No sooner are they posted than they are wrong, especially a multi-variant benchmark like PDW. Drivers get improved and change the raw performance benchmark, and prices drop over time. Wattage stays pretty consistent under load, but manufactures have been known to detune their parts a bit to get a better power usage measurement.
Summary
We have a new generation of consumers who have to get the most value and performance possible on a limited budget. The new consumer needs more than a single parameter measurement of a product. Using performance, price, and power in combination gives a better view of what to expect for our
investments.
Claiming the first to market with 40nm process technology, ATI has done a process shrink and cost reduction on the 826 million transistor RV740 while keeping 640 processors and GDDR5 support. ATI’s reference design shows 512MB but you’ll probably see partners ship a 1GB variant, and most likely that variant will have OC capability.
The company continues to exploit their first to market position with DX 10.1 and their hardware tessellation, as well as excellent anti-aliasing (AA) and anisotropic filtering. The Radeon 4770 offers CrossFireX support, the latest iteration of the multi-board graphics boosting technology and promises GPU compute capabilities for video transcoding with amazing speed. The new board also supports OpenGL 3.0 which makes it a potential candidate for workstation usage.
Smooth looking
Of the board’s many processing capabilities, including its multi‐sample anti‐aliasing (2, 4, or 8 samples per pixel and constant caches) are extremely useful and seem to work in all the tests we ran. The board offers what ATI is calling CFAA—custom filter anti-aliasing—and claims to have 24 variants of it (we didn’t test them all) including adaptive super‐sampling and multi‐sampling and Super AA (ATI CrossFireX configurations only). And the company claims all anti‐aliasing features are compatible with HDR rendering.
Constant caches store constant values used by shaders, i.e. values that do not change each time a shader is executed. The caches allow these values to be stored on-chip and re-used, rather than having to read them in from memory via texture units.
Custom Filter Anti-Aliasing (CFAA) allows the use of programmable filter kernels for anti-aliasing. AA filters work by sampling color and/or depth multiple times per pixel and then blending them together to produce a single value. 24x means we can use up to 24 samples per pixel in our filters, and “custom filters” support for programmable sample locations and blending functions.
Any display
ATI’s new low cost performance AIB (Source TBD – either JPR or ATI)
The board has a really broad output capability with two integrated dual‐link DVI display outputs each capable of supporting 18‐, 24‐, and 30‐bit digital displays at all resolutions up to 1920x1200 (single‐link DVI) or 2560x1600 (dual‐link DVI). Each includes a dual‐link HDCP encoder with on‐chip key storage for high resolution playback of protected content and there are two integrated 400 MHz 30‐bit RAMDACs that can support analog displays connected by VGA at all resolutions up to 2048x1536. Also, DisplayPort output is supported at 24‐ and 30‐bit displays at all resolutions up to 2560x1600, and of course HDMI output is supported with all display resolutions up to 1920x1080.
There is an S-video output, and a DVI to HDMI adapter that ships with the boards and also allows use of HDMI 8-channel audio. While DisplayPort is supported by the chip, ATI’s reference design does not include DisplayPort connectors. It is up to ATI’s partners to ship a board that includes DisplayPort connectors.
Looking for the sweet spot
Positioning a new product is always a tricky thing. The idea is to position above and below the competition with upward features that beat the competition’s higher priced parts. ATI thinks they’ve done that and using just their own parts offer a pretty broad choice.
| ATI Radeon | HD 4670 | HD 4770 | HD 4850 |
|---|---|---|---|
| Process | 55 nm | 40 nm | 55 nm |
| Transistors | 514 M | 826 M | 956 M |
| Engine Clock | 750 MHz | 750 MHz | 625 MHz |
| Stream Processors | 320 | 640 | 800 |
| Compute Performance | 480 GFLOPs | 960 GFLOPs | 1.0 TFLOPs |
| Texture Units | 32 | 32 | 40 |
| Texture Fillrate | 24.0 GTexels/s | 24.0 GTexels/s | 25.0 GTexels/s |
| ROPs | 8 | 16 | 16 |
| Pixel Fillrate | 6.0 GPixels/s | 12.0 GPixels/s | 10.0 GPixels/s |
| Z/Stencil | 32 | 64 | 64 |
| Z Fillrate | 24.0 GSamples/s | 48.0 GSamples/s | 40.0 GSamples/s |
| Memory Type | GDDR3 | GDDR5 | GDDR3 |
| Memory Clock | 1000 MHz | 800 MHz | 1000 MHz |
| Frame Buffer Size | 512MB/1GB | 512MB | 512MB/1GB |
| Memory Data Rate | 2.0 Gbps | 3.2 Gbps | 2.0 Gbps |
| Memory Bus | 128-bit | 128-bit | 256-bit |
| Memory Bandwidth | 32.0 GB/s | 51.2 GB/s | 64.0 GB/s |
| Maximum Board Power | 59 W | 80 W | 110 W |
The table leaves a bit to be desired however, in that the model numbers don’t reflect the price or performance scale. We compensate for that with the Pmark scores offered later.
The roadmap—is now
The big picture is shown in the current roadmap for ATI products.
Figure 1: ATI’s roadmap now fills all SKUs (Source AMD)
Figure 2: World’s first 40nm GPU chip (Source ATI)
Figure 3: ATI’s RV740 block diagram (Source ATI)
The chip
The RV740, is smallish chip, and very tightly packed to make it even smaller, so in addition to being the first GPU built in 40nm, it’s also one of the smallest high-performance chips
available.
What’s inside the 12.1mm x 11.3mm die are 640 32-bit double precision floating point processors.
The architecture follows the general RV770 design with a few parts left out to reduce the chip size and cost.
Pmark scores
For comparison purposes we compared the ATI Radeon HD 4770 to Nvidia’s GeForce 9800 GTX, which is similar to the company’s renamed GTS 250. This is not exactly an “apples to apples” comparison since the GTX 250 is more expensive than the HD 4770. A closer comparison on price would have been the GTX 240 which is a renamed GeForce 9800 GT, but the problem is we didn’t have one, and couldn’t get one.
We tested the AIBs on two platforms, the AMD Phenom II, and the Intel Ice Dale Core2 Quad. We chose those platforms rather than the high-end Barcelona and Nehalem because we didn’t think a user would buy such a high-end PC and then stick a midrange AIB in it. We felt the Phenom II and Ice Dale were more appropriate for the HD 4770 and GTX 250 buyer.
We did not overclock anything.
Raw scores
As discussed in the Pmark presentation using just the Pmark, or any single test score for a purchase decision, would not be the right choice; therefore, we’ve included the subset scores for the AIBs on the two platforms as well.
Performance per power
How many benchmarks the AIBs got in each platform divided by the watts used is shown in the next two charts.
Figure 4: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX Pmark results on Intel Core2 Quad system (source JPR)
Figure 5: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX Pmark results on AMD Phenom II system (source JPR)
Figure 6: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX Performance/Power results on Intel Core2 Quad system (source JPR)
Figure 7: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX Performance/Power results on AMD Phenom II system (source JPR)
Figure 8: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX Performance/Price results on Intel Core2 Quad system (source JPR)
Figure 9: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX Performance/Price results on AMD Phenom II system (source JPR)
Figure 10: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX 3DMark Vantage results on Intel Core2 Quad system (source JPR)
Figure 11: ATI Radeon HD 4770 vs. Nvidia GeForce 9800 GTX 3DMark Vantage results on AMD Phenom II system (source JPR)
What do we think?
The Radeon 4770 is an amazing amount of product for an amazingly low price. As such, it will set a new standard for the industry and challenge low price suppliers like Matrox and VIA/S3.
The Pmark scores show the dramatic difference one gets in evaluating these two AIBs. If you just look at the 3DMark Vantage scores, the AIBs are quite similar and depending on brand favoritism and maybe a price deal, you could choose either one and be happy, or so it would seem.
But when you factor in the price and the power consumption you get a totally different point of view.
Rumors have been circulating that the new ATI Radeon HD 4770 AIB wouldn’t be available. We asked ATI about that and they told us ATI had an opportunity to ship early, albeit in a little lower volumes than usual. Not really low, just lower than their typical launch volumes. Because of that their partners received a lower allocation than is typical and we’ve heard more than one partner wanted a full allocation as there is a belief this product will be a hot commodity. If there is a shortfall, it will be brief as ATI tells us they have lots of chips coming.
The second rumor was that ATI was having yield problems and had to raise their prices. We asked ATI about that and were told AMD anticipates a net price at launch of the Radeon 4770 to be $99 after $10 Mail in Rebate. The SEP for Radeon 4770 will be $109, and, “by the way, our yields are great.”
Feedback from other sources indicate that this card is still a great part, even if it was $109. ATI says they have not increased their price to partners, they did change their price guidance so the partners might make a little more on each card, and that is based purely on feedback that this card is going to sell very well.
