The Radeon R9 280X Review: Feat. Asus & XFX - Meet The Radeon 200 Series

Launching This Week: Radeon R9 280X

The highest performing part of today’s group of launches will be AMD’s Radeon R9 280X. Based on the venerable Tahiti GPU, the R9 280X is the 6^th SKU based on Tahiti and the 3^rd SKU based on a fully enabled part.

In a nutshell, the R9 280X is designed to sit somewhere in between the original 7970 and the 7970 GHz Edition. For memory it has the same 3GB of 6GHz GDDR5 as the 7970GE, while on the GPU side it has PowerTune Boost functionality like the 7970GE, but at lower clockspeeds. At its peak we’re looking at 1000MHz for the boost clock on R9 280X versus 1050MHz on the 7970GE. Stranger yet is the base clock, which is set at just 850MHz, 75MHz lower than the 7970’s sole GPU clock of 925MHz and 150MHz lower than the 7970GE’s base clock. AMD wasn’t able to give us a reason for this unusual change, but we believe it’s based on some kind of balance between voltages, yields, and intended power consumption.

With that in mind, even with the lower base clock because this is a boost part it will have no problem outperforming the original 7970, as we’ll see in our performance section. Between the higher memory clocks and boost virtually always active, real world performance is going to be clearly and consistently above the 7970. At the same time however performance will be below the 7970GE, and as the latter is slowly phased out it looks like AMD will let its fastest Tahiti configuration go into full retirement, leaving the R9 280X as the fastest Tahiti card on the market.

As an aside, starting with the R9 280X and applicable to all of AMD’s video cards, AMD is no longer advertising the base GPU clockspeed of their parts. The 7970GE for example, one of the only prior boost enabled parts, was advertised as “1GHz Engine Clock (up to 1.05GHz with boost)”. Whereas the 280X and other cards are simply advertised as “Up to 1GHz” or whatever the boost clock may be.

As of press time AMD hasn’t gotten back to us on why this is. There’s really little to say until we have a formal answer, but since these cards are rarely going to reach their highest boost clockspeed (the fact that we can’t see the real clockspeed only further muddles matters) we believe it’s important that both the base clock and boost clock are published side-by-side, the same way as AMD has done it in the past and NVIDIA does it in the present. In that respect at least some of AMD’s partners have been more straightforward, as we’ve seen product fliers that list both clocks.

Getting back to the matter of 280X, let’s put the theoretical performance of the card in perspective. As R9 280X is utilizing a fully enabled Tahiti GPU we’re looking at a full 2048 stream processors organized over 8 CU arrays, paired with 32 ROPs. Compared to the original 7970 this gives R9 280X between 92% and 108% of the 7970’s shader/ROP/texture throughput, and 109% of the memory bandwidth. Or compared to the 7970GE we’re looking at 85% to 95% of the shader/ROP/texture throughput and 100% of the memory bandwidth.

Since this is another Tahiti part, TDP hasn’t officially changed from the 7970GE. The official TDP is 250W and the use of boost should keep actual TDP rather close to that point, though the use of lower clockspeeds and lower voltages means that in practice the TDP will be somewhat lower than 7970GE’s. For idle TDP AMD isn’t giving out an official number, but that should be in the 10W-15W range.

Moving on, the MSRP on the R9 280X will be $300. This puts the card roughly in the middle of the gulf between NVIDIA’s GeForce GTX 760 and GTX 770 with no direct competition outside of a handful of heavily customized GTX 760 cards. Against AMD’s lineup this will be going up opposite the outgoing 7970 cards, depending on which the R9 280X can be anywhere between faster and equal to the outgoing cards, but unlike the 7970s the R9 280X won’t have the Never Settle Forever game bundle attached.

Finally, because the R9 280X is based on the existing Tahiti GPU, this is going to be a purely virtual launch. AMD’s partners will be launching custom designs right out of the gate, and while we don’t have a product list we don’t expect any two cards to be identical. AMD has put together some reference boards utilizing a newly restyled cooler for testing and photo opportunities, but these reference boards will not be sampled or sold. Instead they’ve sent us a pair of retail boards which we’ll go over in the following sections: the XFX Radeon R9 280X Double Dissipation, and the Asus Radeon R9 280X DirectCU II TOP.

Please note that for all practical purposes we’ll be treating the XFX R9 280X DD as our reference 280X board, as it ships at the 280X reference clocks of 850MHz base, 1000MHz boost, 6000MHz VRAM. We expect other retail cards to be similar to the XFX card, although there’s still some outstanding confusion from XFX on whether their card will be a $299 card or not.