Cache performance of AMD’s flagship product Milan-X The EPYC7V73X, a 3D V-Cache CPU, has been tested against standard Milan and has shown staggering results.
AMD’s EPYC7V73X, flagship Milan-X, 3D V cache CPU cache performance tested and also features a better boost design
The flagship AMD EPYC 7V73X CPU delivers 64 cores, 128 threads and a maximum TDP of 280W. The clock speed is maintained at 2.2GHz base and 3.5GHz boost, and the cache amount is driven up to insane 768MB. This includes the standard 256 MB L3 cache that the chip basically has. That is, we are looking at 512MB from the stacked L3 SRAM. That is, each Zen 3 CCD has a 64MB L3 cache. This is an insane increase of 3 times the existing EPYC Milan CPU.
At Performance Teaser, Tech Outlet, Chips and cheese I posted the first performance metric highlighting the 3D V-Cache design of AMD EPYC Milan-X CPUs. Performance was compared to standard EPYC 7763 Milan and EPYC 7V73X Milan-X CPUs. Despite the fact that the Milan-X chip has three times the cache, it was able to maintain much the same latency as previous Milan CPUs. Even an increase in delay of 3-4 cycles is negligible when compared to the amount of LLC obtained with this huge server chip.
AMD EPYC 7V73X Milan-X vs EPYC 7763 Milan CPU Cache Performance Test (Image Credits: Chips and Cheese):
Another interesting thing Chips and Cheese mentioned is not only good cache performance, but also the AMD EPYC Milan-X CPU, which has a slightly slower clock speed (paper), but is standard. It was able to maintain a better boost clock than the Milan CPU. The added performance at the higher clock “effectively counteracts the increased latency cycle” introduced in the 3DV-Cache design.
All I have to say is AMD’s good job. Considering that this is three times the standard Milan L3, this increase in the minimum delay of 3-4 cycles is truly amazing. Currently, the Milan-X clock speed is a bit slower on paper. However, Milan-X seems to have a better boost than standard Milan. This effectively counteracts the slight cycle increase in V-Cache.
A single 3DV-Cache stack includes a 64MB L3 cache on top of a TSV that is already working on an existing Zen 3 CCD. The cache will be added to the existing 32 MB L3 cache for a total of 96 MB per CCD. AMD also states that the V-Cache stack can be up to 8-hi. This means that a single CCD can technically provide up to 512MB of L3 cache in addition to 32MB of cache per Zen 3 CCD. Therefore, with a 64 MB L3 cache, you can technically get up to 768 MB of L3 cache (8 3D V-Cache CCD stack = 512 MB). This will significantly increase the cache size.
AMD has shown a 66% performance improvement in RTL validation with Milan-X compared to standard Milan CPUs. The live demo showed how the Synopsys VCS functional verification test was completed by the Milan-X16 core SKU much faster than the non-X16 core SKU. Chips and cheese More comprehensive performance tests, such as bandwidth numbers and comparisons with other data center CPUs, will be coming soon.
AMD EPYC Milan-X 7003X Server CPU (Provisional) Specifications:
|CPU name||Core / thread||Base clock||Boost clock||LLC (3D SRAM)||L3 cache (V cache + L3 cache)||L2 cache||TDP||Price (retailer)||Price (suggested retail price)|
|AMD EPYC 7773X||64/128||2.2 GHz||3.500 GHz||Yes (64 MB per CCD)||512 + 256 MB||32 MB||280W (cTDP225W down / 280W up)||$ 10,476.99 US||TBA|
|AMD EPYC 7763||64/128||2.45 GHz||3.500 GHz||Not applicable||256 MB||32 MB||280W (cTDP225W down / 280W up)||$ 9424.99 US||$ 7890 US|
|AMD EPYC 7573X||32/64||2.80 GHz||3.600 GHz||Yes (64 MB per CCD)||512 + 256 MB||32 MB||280W (cTDP225W down / 280W up)||$ 6654.99 US||TBA|
|AMD EPYC 7543||32/64||2.80 GHz||3.700 GHz||Not applicable||256 MB||32 MB||225W (cTDP225W down / 240W up)||$ 4291.99 US||$ 3761 US|
|AMD EPYC 7473X||24/48||2.80 GHz||3.700 GHz||Yes (64 MB per CCD)||512 + 256 MB||12 MB||240W (cTDP190W down / 250W up)||$ 4643.99 US||TBA|
|AMD EPYC 7443||24/48||2.85 GHz||4.000 GHz||Not applicable||128 MB||12 MB||200W (cTDP165W down / 200W up)||$ 2293.99 US||$ 2010 US|
|AMD EPYC 7373X||16/32||3.05 GHz||3.800 GHz||Yes (64 MB per CCD)||512 + 256 MB||8 MB||240W (cTDP190W down / 250W up)||$ 5595.99 US||TBA|
|AMD EPYC 7343||16/32||3.20 GHz||3.900 GHz||Not applicable||128 MB||8 MB||190W (cTDP165W down / 200W up)||$ 1784.99 US||$ 1565 USA|
https://wccftech.com/amd-epyc-7v73x-cpu-with-3d-v-cache-tested-milan-x-offers-impressive-cache-latency-better-boost-clocks-versus-standard-milan/ Milan-X offers impressive cash latency and a better boost clock compared to standard Milan