AMD Navi 21 to feature 80 CUs, Navi 22 – 40 CUs and Navi 23 – 32 CUs

Published: 26th Sep 2020, 15:44 GMT   Comments

Looks like we have new data on Navi 2X graphics processors. 

AMD Navi 21 – 80 CUs, Navi 22 – 40 CUs, Navi 23 – 32 CUs

The speciations of the Navi 21 and Navi 22 were already ‘confirmed’ by AMD through ROCm 3.8 software update earlier. The data was pieced together by a Redditor stblr. It seems that the same user now has an update featuring Navi 23 and upcoming APUs.

The data provides the most basic speciations for upcoming GPUs and APUs such as Compute Unit count, boosts clocks, and power targets. The values were extracted from macOS 1 1 beta already containing the firmware for the ‘AMDRadeonX6000’ series.

Judging from the frequency listed in the data, we can guess that these correspond to the Radeon Pro series. For instance, the freq_table_gfx[1] (MHz) of Navi 10 is 1400 MHz, similar to Radeon Pro 5700 with a boost clock of 1350 MHz. As we know  Radeon RX 5700 XT has a boost clock of 1755 MHz, so what this means it the clock speeds could be even higher. For Navi 23 and Navi 31, the frequencies and power limits are still missing.

AMD RDNA Graphics Processors
Navi 10Navi 14Navi 21Navi 22Navi 23Navi 31
Compute Units
 
40
 
24
 
80
 
40
 
32
 
80
GPU Clock
 
1400 MHz
 
1900 MHz
 
2050-2200 MHz
 
2500 MHz
Power Limit
 
180W
 
110W
 
200-238W
 
170W

Navi 21 – Sienna Cichlid – Big Navi

This GPU would allegedly feature up to 80 Compute Units (5120 Stream Processors if each CU has 64 cores). The variant listed in macOS11  appears to have a boost clock at 2050 MHz with Navi 21A variant and up to 2200 MHz with Navi 21B variant.

With a boost clock of 2200 MHz, the Navi 21B would have a shader performance of 22.5 TFLOPs. For comparison, with NVIDIA’s new dual SM architecture, the GeForce RTX 3080 graphics card has a maximum FP32 throughput of 29.8 TFLOPs.

Navi 22 – Navy Flounder

The mid-tier GPU in a lineup appears to feature 40 CUs, so just as many as Navi 10. Therefore, the GPU is expected to be an RDNA2 version of mid-range graphics for the upcoming RX 6700 series. The GPU is listed with a (maximum) GPU clock of 2500 MHz, so even higher than Navi 21.

Navi 23 – Dimgrey Cavefish

The entry-level GPU called Navi 23 is also listed in the firmware.  Judging from the data collected by the Reddit stblr, we can conclude that the full number of CUs is 32 (so around 2048 Stream Processors). The frequency charts are not featured in the firmware yet.

Navi 31

The first RDNA3 GPU is also listed on the firmware. The GPU appears to feature the same CU count as Navi 21, meaning we are looking at a refresh under a new microarchitecture. Thus, the Navi 31 GPU would also feature 5120 Stream Processors. We are not yet sure what are AMD intentions with Navi 31, but one would guess it will end up in RX 7000 series and future Radeon Pro SKUs for Apple Mac.

The full GPU charts posted by stblr

[reprinted with permission]

AMD RDNA Discrete GPUs
PropertyNavi 10Navi 14Navi 12Navi 21Navi 22Navi 23Navi 31
num_se2124224
num_cu_per_sh1012101010810
num_sh_per_se2222222
num_rb_per_se8884444
num_tccs168161612816
num_gprs1024102410241024102410241024
num_max_gs_thds32323232323232
gs_table_depth32323232323232
gsprim_buff_depth1792179217921792179217921792
parameter_cache_depth1024102410241024102410241024
double_offchip_lds_buffer1111111
wave_size32323232323232
max_waves_per_simd20202016161616
max_scratch_slots_per_cu32323232323232
lds_size64646464646464
num_sc_per_sh1111111
num_packer_per_sc2224444
num_gl2aN/AN/AN/A4224
unknown0N/AN/AN/A1010810
unknown1N/AN/AN/A1612816
unknown2N/AN/AN/A80403280
num_cus (computed)40244080403280
AMD RDNA Discrete GPU Frequencies
PropertyNavi 10 aNavi 10 bNavi 14Navi 21 aNavi 21 bNavi 22
gfxclk (MHz)300 – 1000300 – 1000300 – 1900500 – 2050500 – 2050500 – 2500
uclk (MHz)100 – 750100 – 750100 – 875577 – 1089577 – 1089577 – 1089
socket_power_limit_ac[0] (W)180180110200238170
freq_table_gfx[0] (MHz)300300300500500500
freq_table_gfx[1] (MHz)140014001900205022002500
freq_table_uclk[0] (MHz)12410010010010097
freq_table_uclk[1] (MHz)500500500500500457
freq_table_uclk[2] (MHz)625625625625625674
freq_table_uclk[3] (MHz)875750875100010001000

AMD APUs

The leak also covers the specs of upcoming AMD APUs. The long-discussed Cezanne is the upcoming Zen3 based mobile architecture, featuring identical an idnetical core configuraiton to Renoir. The series is expected to feature up to 8 Compute Units of GCN (Vega) graphics and up to 8 CPU cores.

Meanwhile, Van Gogh will be the first architecture to feature RDNA2 graphics. It would retain the same number of CUs as Renoir and Cezanne – up to 8.

Things get a lot more interesting as we move to Rembrandt. According to leaked roadmaps, Rembrandt will be a successor to Cezanne. The series would rely on RDNA2 graphics and a new fabrication process (rumored to be 6nm). The chart only covers the GPU configuration of the architecture, but one would guess that a more efficient node and next-generation graphics will provide a substantial boost to AMD mobile offer.

AMD Rembrand is also rumored to feature a PCIe 4.0 interface, which is huge news for those waiting for high-end GPUs being offered alongside AMD Ryzen processors. The PCIe 3.0 x8 interface was a bottleneck that prevented notebooks makers from offering more powerful discrete graphics.

AMD GCN (Vega) and RDNA APUs
PropertyRenoirCezanneVan GoghRembrandt
num_se1111
num_cu_per_sh8886
num_sh_per_se1112
num_rb_per_se2224
num_tccs4444
num_gprs25625610241024
num_max_gs_thds32323232
gs_table_depth32323232
gsprim_buff_depth1792179217921792
parameter_cache_depth10241024512256
double_offchip_lds_buffer1111
wave_size64643232
max_waves_per_simd10101616
max_scratch_slots_per_cu32323232
lds_size64646464
num_sc_per_shN/A111
num_packer_per_scN/A224
num_gl2aN/AN/A44
unknown0N/AN/A86
unknown1N/AN/A44
unknown2N/AN/A812
num_cus (computed)88812

Leaked AMD CPU and APU Roadmaps, Source: @MebiuW

Source: stblr @ Reddit




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