Everything you need to know about AMD’s “missing” 7800 XT and 7700 XT GPUs

Where are you navi 32?

AMD launched the Radeon RX 7900 XT and XTX GPUs last year. The RX 7600 arrived in May. But here we are at the end of June and AMD still hasn’t announced that it will be complementing its RDNA 3 lineup with the 7800 XT and 7700 XT, as well as the non-XT versions. So what exactly is going on?

The first thing to note is that the RX 7800 and 7700 cards aren’t far behind. The RX 6700 XT launched in March 2021, so one might expect the 7700 XT in March of this year. At worst, the 7700 XT is a few months late.

As for the 7800 XT, it’s a bit more complicated. AMD rebranded with 7900 XT and 7900 XTX. When RDNA 2 launched in late 2020, the 6900 XT was the top performing card, with the 6800 XT just below, based on the same Navi 21 GPU.

So you could say the 7800 XT is actually here, it’s just called the 7900 XT. But of course we’re still missing a replacement for the RX 6800 which isn’t an XT. and the 6700 XT and non-XT 6700 mentioned above.

Either way, there’s a huge hole in the middle of the RDNA 3 lineup. That’s where the latest rumors come from. One of the main talking points has to do with alleged “leaks” claiming that the 7800 XT will in fact be based on the same Navi 31 GPU as the current 7900 XT and XTX.

It makes perfect sense and wouldn’t come as a surprise. Whether the 7800 XT is the replacement for the last-generation 6800 XT or a non-XT 6800, being based on the largest available GPU would be in line with AMD’s earlier approach.

It so happens that AMD already has a Navi 31 redesign in the Radeon Pro W7800. This is a professional GPU, not a gaming card, but it uses a Navi 31 mini GPU with 70 CUs and 4480 shaders. If you forgot, the 7900 XT has 84 CUs and 5376 shaders, while the 7900 XTX has 96 CUs and 6144 shaders.

So AMD has something ready that could fill the 7800 XT’s role. What about the 7700 XT? This is where Navi 32 comes in. This is where things get a little speculative. The best current information indicates that the Navi 32 is a small chip model, like the Navi 31, but with a smaller graphics chip and just four MCDs instead of six, the latter being those small chips that house the cache and memory controllers.

This GPU was recently spotted at an AMD silicon presentation during an interview with company CEO Lisa Su. Four 256-bit MCDs will provide the 7700 XT in terms of memory bus width, but one of the four MCDs can be a dummy inserted for packaging purposes. The three MCD arrangement will result in a 192-bit bus and allow for a 12GB 7700 XT card, which is what we’d expect.

Either way, Navi 32 is generally believed to pack 60 or 64 compute units, which is the upper limit for the 7700 XT card, although some rumors suggest that the 7700 XT uses a miniature Navi 32 GPU with only 54 compute units. Some rumors indicated that there might only be 48 UAs.

In fact, there could be a non-XT 7800 with 60 or 64 CUs enabled. This GPU will then use all four MCDs, run on a 256-bit bus, and provide 16GB of VRAM.

Incidentally, this maximum number of 60 to 64 controllers for Navi 32 also explains why it is unlikely to be used in the 7800 XT. There simply isn’t enough CPU for this class of GPU. It will hardly, if at all, be faster than the old 6800 XT and 72 RDNA 2 units.

When it comes to the performance of these cards, Navi 31 is a known amount and based on the W7800 professional card, Igor’s Lab recently calculated that the 7800 XT will be on average slightly faster than the last generation 6900 XT. Decent, but not amazing.

On the other hand, the 7700 XT could be a bit more exciting. Remember, the 7800 XT is built on 70 CU RDNA 3, while the 6900 XT has an old school 80 CU RDNA 2. In other words, less CPU, but slightly higher performance.

7700 XT CPU number not confirmed. My old 6700 XT has 40 CU RNDA 2. So even 48 CU RDNA 3 should be a good step up, while 54 CU would be better. Of course, we have no idea how powerful Navi 32 is, which is an important part of the picture.

As is, of course, the release date of one of these new GPUs. Unfortunately, there is no exact date. Most of the current rumors point to a third-quarter launch, likely in September. Given the rarity of information leaks, it doesn’t seem like new AMD GPUs are imminent.

The remaining question is why we haven’t seen these new maps yet. One possibility is that AMD still has a lot of last-gen 6700, 6800, and 6900 derivatives that it needs to move over and so doesn’t want to add new GPUs.

The other possibilité is a problème technique with Navi 32. Sependant, this does not work with the launch of the 7800 XT base on Navi 31. And so do our avons refer to more reprises, the GPU vents are still unavailable. At the moment. So the GPU glut theory seems to be the most plausible explanation.

This pretty much sums up the best information available on upcoming AMD GPUs. Briefly ? Expect to see the 7800 XT and 7700 XT in September, with potential non-XT variants to follow.