ATI Radeon X850XT Platinum Edition AGP (R481)

The past year 2004 was memorable not only for the vast changes in the graphic industry related to the release of new chips, transition to the PCI-Express and other important events. We also remember the year 2004 for its unprecedented shortage for top-end solutions, which is still felt even today. The first six months after the announcements was something really dreadful. Needless to say, such a shortage gave rise to absolutely inadequate prices. From the sellers' viewpoint, all is right and logical - they buy it all anyway, even queue for it. Why should we waste time on trifles?

Then in the AGP sector there occurred some calm - manufacturers threw out all their hidden reserves onto the young and dynamic market of PCI-E solutions. An awful lot of new chips was produced, and a flood of new cards on their base. LE, GT, XT, PE, TC, HM, etc.- you never make head or tails of that. Meanwhile, all was still the same in the AGP high-end sector - 6800Ultra/GT and RX800XT(PE)/PRO.

All remember it quite well how the situation with these cards was going on then, and the approximate performance ration has been known to everyone as two by two. So we are not dwelling on that - we are in for a very interesting introduction to a new product of the AGP market presented by ATI Technologies - Radeon X850 XT PE based on R481.

Last month, ATI finally recalled the AGP sector of the market of graphic accelerators and released a few new solutions.

These are first of all RX800XL and RX800 equipped with the transition bridge RIALTO which is in charge of support for the AGP interface. In one of our previous reviews we already explored the performance of RX800XL AGP, so we'll return to the topic several times in what follows.

Also, RX700 boards are coming up which are meant to bring in a revolution into the mainstream sector. We haven't yet held any of the card specimens on hands, so there is nothing certain we can tell regarding that - waiting for engineering samples and would be glad to share the benchmarking results with you.

The third novelty of the AGP sector is R481-based Radeon X850XT PE. The card is fundamentally different from its recently announced congeners for the native support of AGP interface. In all the remaining aspects, it is the same R480 chip made in the 0.13 process technology with the low-k. The PCB design has remained the same, in particular, the "two-tiered" cooling system and a list of supported technologies. That is, we have essentially got another direct heir to R420 which first transformed to R423 (with the native support for PCI-E), then to R480 (which is an optimized chip R423 + a new design of the cooling system), and now, having acquired the native support for AGP, has turned into R481. It's all simple.

There comes up quite a reasonable question - what was the use of releasing a new chip if it could have been done the way it was in the mainstream - through a mere addition of the RIALTO bridge? Most likely, that was caused by the reluctance to complicate the wiring, or probably by that it would be better to use a ready-made R420 interface unit. Perhaps, all these reasons altogether plus the marketing considerations. Somehow or other - we have got a new high-end solution.

The standard operating frequencies of RX850XT (in the Platinum Edition version) are 540/1180MHz, that is - the same as in RX850XT PE based on R480. The recommended (!) price hasn't changed either - $549. Again, this figure shouldn't be taken seriously - it may be priced at a whatever level, especially for the first time.

Note also that there is the RX850XT non PE version on the base of R481. The difference as usual is in the frequencies downstated relative to Platinum Edition, so the recommended price is also lower and is set at $499.

As regards the RX800XT(PE)/PRO based on R420, they will be gradually expelled from the retail stores by R481 and R430. That is, the high-end sector will be completely reconstructed. That is logical - keeping both R420 Series and R481/430 Series for AGP would be quite costly and non-reasonable. Of course, that won't happen in a fortnight, and we'll still be seeing X800XT (PE)/PRO for quite a long time. By the way, RX800XT PE AGP can be currently made available at about $500+ (depending on the manufacturer and sales outputs). The price for the competitor product - GeForce 6800Ultra -falls within the same limits. It's no use here setting exact figures - offerings at $515 and $600+ can be found. The price is in strong dependence on the manufacturer.

Participants of our benchmarking session are both GeForce 6800Ultra (including the one overclocked to the frequencies of 6800Ultra Extreme - 450/1100MHz) and the previous "king of the hill" by ATI - Radeon X800XT PE (R420).

ATI RX850XT PE Features

The video card specimen to be tested is a reference board by ATI and is shipped in a small box. Of course, the batch-produced solutions which our Canadian partners are submitting to us soon will do please by both the rich package bundle and other nice bonuses, and not all manufacturers will equip their boards with a dual-slot cooling system.

That was a special fun to see the inscription "Powered to play DOOM3" close to the logically expected "Preferred graphics for Half-Life2".

The cooling system installed on RX850 XT PE has undergone substantial changes as compared to the previous flagship solutions (it's the first time ATI uses a dual-slot design for the cooling system) and is completely identical to what we saw on R480. The graphic processor is cooled by a copper radiator. The fan takes air from the CPU housing, runs it through beneath the cover and blows it outside through holes in the cap. All that is fastened with two screws and a plate on the board's reverse side.

To prevent the small components from damage upon the contact of the screws with the textolyte, there are protective "washers" placed between them. To cool the four memory chips positioned on the reverse side of the board, a separate aluminum plate is used. Remember that in ATI's previous flagship - X800XT PE - no cooling for the memory chips positioned on the reverse side of the board was provided at all.

The card offers 256 Mb of GDDR3 memory with a 256-bit data transmission bus assembled of eight Samsung BGA memory chips of 1.6 ns access time, which is equivalent to 625 MHz (1250 MHz DDR) operating frequency. The standard operating frequency of the memory on ATI RX850XT PE is 590 MHz (1180 MHz DDR). The memory chips are positioned in four along each side of the PCB.

The graphic processor R481 runs at 540MHz, offers 16 pixel pipelines and 6 vertex units.

The manufacturer used the "jewel steel" for GPU as the thermal interface and thermal spacers for the video memory chips.

The card supports for VIVO features implemented on the ATI Rage Theater chip,

is equipped with a connector for additional power supply,

and with a standard set of outputs - analogous, digital, and VIVO.

Test configuration

For benchmarking ATI RX850XT PE and RX800XT PE we used the most recent WHQL-drivers - Catalyst 5.4, and beta version of ForceWare 76.50 for GeForce 6800Ultra.

Overclocking

We overclocked the card with ATI Tray Tools.

Initially, we didn't build much hope for the card's overclocking capability because even without that top-end solutions normally run at the breaking point, and the default frequency of the chip is mostly dependent on the yield rate of chips able operating at a certain frequency. We relied more upon overclocking of the video memory - it runs initially at 1180 MHz DDR, while the memory default frequency at 1.6 ns is 1250 MHz DDR.

On the other hand, remembering our experiments on overclocking R480-based boards whose results proved not to be the most impressive (up to 570 MHz on Gigabyte RX850XT PE GPU, and up to 585 MHz on ASUS EAX850XT PE, whereas the video memory failed to overclock at all, in none of the cards), we took overclocking of this RX850XT PE specimen with a large part of skepticism.

However, the overclocking capabilities of this board surpassed all our boldest expectations. Without use of additional blowing or other modifications to the standard cooling (except for the replacement of the thermal interface with "Alsyl-3"), we were able to overclock ATI RX850XT PE on our regular open test bench (ambient temperature = 28 C) to as high as 587/1290 (!!!)MHz. The video memory offers simply fantastic overclocking, and the chip performs not worse. But note that our overclocking results do not apply to other similar boards. So, let's not refrain your curiosity and get down to the most interesting part - the benchmarking.

Performance and conclusions

We can ascertain an emergence of new and very strong contender for undisputable leadership in the high-end sector of the AGP market. The novelty has won at most tests (except DOOM3 and HALO) over the competitor solution - GeForce 6800Ultra. As regards the GeForce 6800Ultra (Extreme) overclocked to 450MHz for the chip, it is approximately on par at performance. Both cards demonstrate a performance so high at all modern games (let alone the past-generation games) that the 5-10 FPS difference in fact does not matter. That is not low-end where even 3-5 FPS already matter. RX850XT PE is also superior at performance over the ATI's ex-flagship - RX800XT PE.

Besides, the card surprised and pleased us by its outstanding overclocking capability. At the standard cooling, we were able to overclock RX850XT PE to 587/1290(!!!)MHz. The overclocking proved successful, especially for the video memory (access time - 1.6 ns, with the nominal 1250 MHz DDR). I wonder how the overclocking would go up under additional cooling or after its radical modification.

Of course, not every specimen of the card is able working such overclocking miracles, but for now we mention only that particular case.

The only fly in the ointment was the matter of price and its availability on sales. However, this time ATI has also proved on par - judging by the Moscow prices, RX850XT PE can already be made available, and the price starts just with $550, which is equivalent just to the recommended price. With this situation, the reason for purchasing RX800XT PE now is doubtful, and the lifetime for video cards based on R420 after the announcement of R481- and R430-based AGP solutions can be regarded as coming to an end.

In the upshot:

You have been presented the reference video card ATI RX850XT PE, a new flagship of the AGP market. Soon, we are also reviewing first batch-produced solutions on the base of R481 - e.g., a board by Sapphire. For the moment, RX850XT PE is the most powerful modern AGP video card by the Canadian company, and the specimen in question has pleased us immensely by its superb overclocking capability. Of special mention is that despite the relatively small time passed since the announcement, these cards can be already made available in the retail and at quite adequate prices which don't strongly differ from the recommended $549. Based on that, we decided to award ATI RX850XT PE with our "Editor's Choice" medal.