Of course, when AMD launches the RX 6600XT and RX 6600 soon, we’ll already know most of it. With Navi23 AMD relies, as already with the RX 5500XT and Navi13, on a chip that can be used both as an external graphics card and in the notebook as a dedicated chip. This has advantages and disadvantages, as we will see in a moment. However, in today’s article I would like to take a closer look at the technology and the details of Navi23 and leave aside the usual performance estimates from various leaks, because these could be somewhat off the mark in the later practical use of these cards.
But first, let’s get to the chip itself. The die sits on the package rotated by 45°, as we already know from the older Radeon chips. The dimensions of the rectangular die are 16.51 mm x 14.28 mm, which results in an area of 235.76 mm². The whole package measures 35 x 35 mm and is therefore square. AMD specifies +/- 0.1 mm as height tolerance for the entire package (BGA) including the die, which results in a tolerance range of 0.2 mm in total.
In practice, however, this should rarely have an effect unless the packager is having a bad day. The following graphic shows the complete package and the die. I have intentionally reduced the size of these (and the other graphics) and slightly alienated them, as well as removed the original watermarks, in order to protect the source.
Before I get to the specifics of the memory, I’ll quickly summarize the possible desktop models along with the already launched cards in the table below. Entries marked with * are not yet confirmed with official slides or statements, but are based on various sources from the AIB and OEM series of board partners or notebook manufacturers who will install these chips both on discrete graphics cards and together (especially with Ryzen CPUs and Smart Shift) in notebooks.
Since AMD is obviously planning three Navi23 Mobile GPUs for the RX 6000M family, the staggering of 90 W, 80 W and 65 W for the GPUs is now considered set. However, this performance information is based on TGP (Total Graphics Power, GPU, Memory and Storage Controller). It is very likely that the maximum TBP of the mobile variants including all other losses could be just over 100 W, although you always have to calculate slightly differently for notebooks anyway.
Laptop manufacturers will then decide for themselves which TGP to select for their own designs, and only premium models with sufficient cooling solutions should then rely on the 90W variant. The following is an excerpt from an evaluation BIOS for mobile use as a notebook graphics with 90 Watt TGP, as I was able to read it some time ago:
We can see that the limitation of the TGP on the mobile used chips is something that should of course also affect the maximum clock, which should then be set much lower at 300 to 400 MHz when boosting, if we follow the values of the last evaluation boards and firmware versions. I will certainly report separately on Navi24 and the RX 6500/6400(M) models when the time is right. The fact that an RX 6600XT still doesn’t come too close to a rumored RX 6700 isn’t just due to the clock and the somewhat narrower memory interface, but I’ll get to that in a moment.
|Model||RX 6600||RX 6600 XT||RX 6700 XT||RX 6800||RX 6800 XT|
|GPU||Navi 23||Navi 23||Navi 22 (XT?)||Navi 21 XL||Navi 21 XT|
|Process node||7 nm|
|The Size||236 mm²||336 mm²||520 mm ²|
|TMUs/ROPs||112 / 32*||128 / 32*||160/64||240 / 96||288 / 128|
|Game clock||TBC||TBC||2424 MHz||1815 MHz||2015 MHz|
|Boost Clock||< 2600 MHz*||< 2700 MHz*||2581 MHz||2105 MHz||2250 MHz|
|Memory size||8 GB GDDR6||12 GB GDDR6||16 GB GDDR6|
||64 MB||96 MB||128 MB|
|Memory clock||16 Gbps|
|Bandwidth||256 GB/s||384 GB/s||512 GB/s|
|TDP||TBC (< 100 W*)||TBC (< 130 W*)||230 W||250 W||300 W|
The chips are said to support DirectX12 feature level 12_1, Vulkan 1.1, OpenGL 4.6 and OpenCL 2.2. Also, AMD Liquid VR should be supported. The rest of the feature list is similar to that of a Radeon RX 6700 XT, so I can save redundant content with already known features at this point.