Unofficially it went with the ComboAM4PI V2 126.96.36.199 already longer, but since 03.03.2021 AMD announced also officially the support of Zen2. Up to now, AMD required a current Zen3 CPU, a B550 or X570 motherboard and an updated BIOS. Or just a current Intel solution. Now also officially Zen2 and it is time to draw here once the direct comparison, what the native implementation of Zen3 and the partly over the firmware adapted use of Zen2 also with the performance differs. Or maybe not? Let’s be surprised!
A current Ryzen 9 5900X as well as a Ryzen 9 3900XT are used, which run with the used graphics cards in form of a Radeon RX 6800 16 GB reference and the KFA2 GeForce RTX 3060 EX 12 GB on a MSI MEG X570 Godlike, for which a suitable BIOS is also available in the meantime. As an example, I chose Borderlands 3 as the game, because here the advantages of using the Resizeable BAR (yes, it’s factual and not a counter!) come into their own particularly well. Badass settings and Full HD vs. WQHD against a Radeon RX 6800 and a GeForce RTX 3060, neither of which are likely to let the CPUs become a bottleneck in this case.
But first we have to clarify the term BAR, i.e. Base Address Register.
What is behind Resizeable BAR?
Behind this, meanwhile often used buzzword, is actually nothing else than the clever handling of the Base Address Register (BAR) and exactly this support must be integrated and also activated in the substructure. Resizable PCI BARs (see also PCI SIG from 4/24/2008) have been playing an important role in modern AMD graphics hardware for quite some time, since the actual PCI BARs are normally limited to 256 MB, while the new Radeon graphics cards now offer up to 16 GB VRAM and the GeForce RTX 3060, the only supported graphics card from NVIDIA so far, still offers 12 GB.
As a result, only a fraction of the VRAM is directly accessible to the CPU, which without the feature requires a whole bunch of workarounds in the so-called driver stack. Of course, this always costs performance and should therefore be avoided. AMD and meanwhile also Intel are now starting exactly there. This is not really new, but it must be implemented cleanly in the UEFI and later also activated. This only works if the system is running in UEFI mode and CSM/Legacy are disabled.
CSM stands for the Compatibility Support Module. The Compatibility Support Module is exclusive to UEFI and ensures that older hardware and software will work with UEFI. The CSM is always helpful when not all hardware components are compatible with UEFI. Some older operating systems and the 32-bit versions of Windows also do not install on UEFI hardware. However, it is precisely this compatibility setting that often prevents the clean Windows variant required for the new AMD components from being installed.
Benchmarks, test system and evaluation software
The benchmark system has been tweaked and I’m also going with PCIe 4.0, the matching X570 motherboard in the form of the MSI MEG X570 Godlike, and both the second and third generation Ryzen 9s running water cooled but not manually overclocked any further. Add to that the matching DDR4 3600 VIPER from Patriot, as well as several fast NVMe SSDs. The memory runs with identical settings on both CPUs, which naturally promotes comparability.
I have also summarized the individual components of the test system in a table:
|Test System and Equipment
||AMD Ryzen 9 5900X / Ryzen 9 3900XT
MSI MEG X570 Godlike
2x 16 GB Patriot DDR4 3600 VIPER
1x 2 TB Aorus (NVMe System SSD, PCIe Gen. 4)
1x 2 TB Corsair MP400 (Data)
1x Seagate FastSSD Portable USB-C
Be Quiet! Straight Power 11 1000 Watt Platinum
||Alphacool Ice Block XPX Pr
o Alphacool Ice Ball, 360 Radiato
r Alphacool Subzero
||MCU-based shunt measuring (own build, Powenetics software
) Up to 10 channels (max. 100 values per second
) Special riser card with shunts for the PCIe x16 slot (PEG
NVIDIA PCAT and FrameView 1.1
||1x Optris PI640 + 2x Xi400 Thermal Imagers
Pix Connect Software
Type K Class 1 thermal sensors (up to 4 channels)
|OS:||Windows 10 Pro (all updates, current certified or press drivers)|