Radeon RX 7900 XT and XTX Specifications

There are several differences between RDNA 2 and RX 7900 XT. However, the RX 7900 XT has 20% more Compute Units (CUs) and doubles the number of FP32 (32-bit floating point) computing functionality per CU. AMD still employs 64 Streaming Processors (SPs) per CU; however, that amount is more like double in many respects. Each GPU holds a single GCD chiplet (Graphics Compute Die) and up to six MCD chiplets (Memory Cache Die). The XTX has a fully enabled GCD and six MCDs. In contrast, the XT has a partially enabled GCD with 84 CUs and five MCDs — the sixth MCD slot will remain occupied, either with a dummy piece of silicon or a non-functional MCD (non-functional because it is fused off, though it may or may not be defective). Transistor counts have increased significantly compared to the previous generation RX 6000-series, with 58 billion total transistors compared to only 26.8 billion on Navi 21. Theoretical computation has increased by up to 159% compared to the RX 6950 XT, with 61.4 teraflops on the XTX card and 51.6 teraflops on the XT variant.

Radeon	RX 7900 XTX	RX 7900 XT	6950 XT
GPU	Navi 31 XTX	Navi 31 XT	Navi 21 KXTX
Process Node	5nm+6nm	5nm+6nm	7nm
Die Size	308mm2 (single GCD) 533mm2 (with MCDs)	308mm2 (singleGCD) 533mm2 (with MCDs)	520mm2
Transistors	58 Billion	58 Billion	26.8 Billion
Compute Units	96	84	80
Raytrace Units	96	84	80
Stream Processors	6144 (12288)	5376 (10752)	5120
TMUs/ROPs	192	192	128
Game Clock	2.3 GHz	2 GHz	2100 MHz
Boost Clock	2.5 GHz	2.5 GHz	2310 MHz
FP32 TFLOPs	61 TFLOPs	52 TFLOPs	23.65 TFLOPs
Memory Size	24 GB GDDR6	20 GB GDDR6	16 GB GDDR6
Infinity Cache	96 MB	80 MB	128 MB
Memory Bus	384-bit	320-bit	256-bit
Memory Clock	20 Gbps	20 Gbps	18 Gbps
Bandwidth	960 GB/s	800 GB/s	576 GB/s
Effective Bandwidth	3500 GB/s	2900 GB/s	1794 GB/s
TBP	355W	300W	335W
PCIe Interface	PCIe 4.0 x16	PCIe 4.0 x16	PCIe 4.0 x16
Price	$999	$899	$1099 US

Radeon RX 7900 XT and XTX 

Radeon RX 7900 XT has 20GB of GDDR6 VRAM and 10,752 shader cores, it will not be as fast as the RTX 4090, which closes in at 100 teraflops but might match the 4080. Instead, it looks like the RX 7900 XT may aim for 52 teraflops if it launches with the above core specs. The XTX is listed at 61 TFLOPS. AMD turned off some shading units on the Radeon RX 7900 XT with 20GB to reach its target performance. This is different from the fully unlocked Radeon RX 7900 XTX, which uses the same GPU but has all 12288 shaders turned on. The AMD Radeon RX 7900 XT uses two slots, so it gets power from two 8-pin connectors. The maximum board power it can use is 300W. There is one HDMI 2.1 output and three DisplayPort 2.0 outputs. During the presentation, there was no mention of PCI-Express 5.0 x16 connects, so it's PCI-Express 4.0  for Radeon RX 7900 XT connects to the rest of the system. The card will cost $899 Radeon RX 7900 XTX will have 24GB of GDDR6 VRAM and the complete 12,288 shader cores, it will probably get closer to the RTX 4090 thanks to its infinity cache as well. As mentioned AV1 en/decode is present. TBP is 355 Watt, and this card will cost $999 

Architecture

When it comes to the graphics processing unit, things start to heat up. Even though the 58 billion transistors in AMD's new GPUs are not all in one spot, the company claims they are the fastest ever built. AMD quickly points out that these are the first gaming GPUs to use a chiplet architecture. Based on the company's experience developing chiplet-based Ryzen central processing units, AMD added two new key components to the RDNA 3 GPU: a GPU chiplet (GCD) and memory chiplets (MCD).  Six MCDs will surround this GCD on both cards. These are substantially smaller chips than the GCD, measuring 37mm2. These are constructed on TSMC's 6nm manufacturing node. Each of them has a 64-bit memory controller as well as a second-generation Infinity Cache. All six of these MCDs will work on the RX 7900 XTX. On the RX 7900 XT, only five of them will function. The sixth chip will remain, but AMD claims it is for manufacturing reasons (structural stability), which I assume means it is for the packaging process and possibly for optimal cooling. That means the 7900 XTX should have 96MB of Infinity Cache, whereas the 7900 XT has  80MB. The Navi 31 GPU has made numerous appearances in leaks and rumours over the past year. This GPU is made in 5nm and has up to 12288 shader processors and 96MB of Infinity Cache. For the Radeon RX 7900 XTX, this graphics processor is stated to handle a 384-bit memory bus and capacities of up to 24GB of GDDR6 20 Gbps. AMD now touts multiple clock domains; for the XTX, that's 2.3 GHz for the shader clock frequency and 2.5 GHz for the front-end clock speed. That helps them save energy. RDNA 3 employs split clocks in the shader and front-end. According to the company's developers, the front-end was limiting gaming performance more than the shaders themselves. In RDNA 3, splitting the shader clock and the front-end clock allows for a faster front-end frequency of up to 2.5GHz and a slower shader rate of 2.3GHz. According to AMD, this amounts to a 15% frequency increase while preserving a 25% power savings. The company will launch its high-end series based on the Navi 31 GPU, with Navi 32 and 33 following later. AMD's next-generation RDNA 3 GPUs will use WGP (Work Group Processors) instead of CU (Compute Units). Each WGP will have two CUs, but each CU will have four SIMD32 clusters instead of just two on each CU in RDNA 2. There are also AI units present; though we lack full information, these seem to be Tensor equivalents.  The RDNA 3 architecture of the AMD Navi 31 GPU has one GCD (Graphics compute die) based on Dual SIMD units, effectively doubling up shader count. The RX 7900 XTX features 96 CUs, each with 64 dual-issue processors. These processors can process two instructions down each data path, resulting in twice the instruction issue rate of RDNA 2. It is not two times faster; instructions can just be executed twice as quickly. Each CU also includes a pair of AI accelerators for operations like matrix multiplication, as well as a second-generation ray tracing accelerator. This RT accelerator, according to AMD, supports additional instructions and ray box sorting, resulting in up to 50% improved ray tracing performance per CU. Finally, each CU includes a Vector General Purpose Registry (VGPR), which is essentially where the CU's instructions are stored. This will give 12,288 shader processors for the fully enabled GPU, also called stream processors. Compared to the 5120 SPs on the Navi 21 GPU, this is 2.4 times as many cores. The Navi 31 GPU will also have 6 MCDs (memory cache die aka infinity cache ships), each of which will have 16 MB of Infinity Cache and 64-bit (32-bit x2) memory controllers, which will give the chip a 384-bit bus interface. These are the chiplets, to one graphics die, and then infinity cache memory dies with controllers. Next-generation raytracing cores should compensate for the performance that the 6000 lacked in Raytracing. Per CU, AMD claims 50% more performance. Also update is the video or media engine, which will support AVC/HEVC simultaneous en and decode, ABV1 8k60 en/decode and AI-enhanced Video encode. on the output front, Displayport P 2.1 is supported with a display link bandwidth of up to 54 Gbps. But let's talk about the cards for a second. Next page, please.