In November 2021, AMD officially launched a new version of the Zen3 processor, adding 3D V-Cache caching technology for the first time, of which the desktop version is the Ryzen 7 5800X3D, with an increase of 64MB cache, and the server version is the Milan-X Xiaolong series, with an additional 512MB cache.
Specifically, the Milan 7003 series originally had up to eight small chips inside, each with 32MB of L3 cache, for a total of 256MB.
The Milan-X 7003X series has an additional 64MB of L3 cache stacked on each chiplet, for a total of 512MB.
If you count the 4MB L1 cache and 32MB L2 cache, a 64-core Dragon has a terrifying 804MB cache, and the two-way is almost 1.6GB!
According to AMD's tests, more cache can greatly reduce the pressure on system memory bandwidth, and the same 16-core Milan-X, Milan, Synopsys VCS measured EDA RTL verification workloads, performance increased by up to 66%.
So what is the actual performance? The biggest worry about increasing the external L3 cache is still latency, in response to this problem, there have been overseas netizens to do a cache delay test, compared with the normal version of the Milan 7003 series processor and Milan-X 7003X series processor.
Whether it is the absolute latency time in the above figure or the latency period in the following figure, the Milan-X 7003X series with 2x L3 cache performs very well, only adding 3-4 cycles, which is very amazing.
They will have very detailed tests in the future, but from the perspective of latency, AMD's 3D V-Cache technology is full of surprises, and the external 2x cache does not bring exaggerated latency.
Although the test is still the server version of the Milan-X 7003X series processor, but the desktop version of the Ryzen 7 5800X3D only added a set of 64MB cache, theoretically the delay performance is better, can offset the impact of frequency reduction, in some cache-eating games should have a surprise performance, AMD officially said that the average performance of 15%, up to 40% performance improvement.