Thursday, January 18th 2024
AMD Ryzen 8000G APU Memory Sweet Spot is DDR5-6000
During CES, PCWorld had a chat with Donny Woligroski, Technical Marketing Manager at AMD. The new Ryzen 8000G APUs were a large part of what covered in the almost 17 minute long video and PCWorld got some details that weren't covered in the official press materials that AMD released at the launch. The officially supported memory speed listed by AMD is DDR5-5600, which is a step up from the official speed of DDR5-5200 for the Ryzen 7000-series CPUs.
However, we know that the Ryzen 7000-series is more than happy to use faster memory and as before, AMD has an unofficial memory sweet spot and just as with the Ryzen 7000-series, the Ryzen 8000G-series of APUs has a memory sweet spot of DDR5-6000. That said, it's unknown if the Ryzen 8000G-series will support faster memory or will start flaking out above DDR5-6000, like many Ryzen 7000-series CPUs do unless you switch to a 1:2 ratio. Woligroski is also pointing out that dual-channel is a must to get the best performance out of the new APUs, although this shouldn't really surprise anyone. Full video after the break.
However, we know that the Ryzen 7000-series is more than happy to use faster memory and as before, AMD has an unofficial memory sweet spot and just as with the Ryzen 7000-series, the Ryzen 8000G-series of APUs has a memory sweet spot of DDR5-6000. That said, it's unknown if the Ryzen 8000G-series will support faster memory or will start flaking out above DDR5-6000, like many Ryzen 7000-series CPUs do unless you switch to a 1:2 ratio. Woligroski is also pointing out that dual-channel is a must to get the best performance out of the new APUs, although this shouldn't really surprise anyone. Full video after the break.
30 Comments on AMD Ryzen 8000G APU Memory Sweet Spot is DDR5-6000
Before I explain further, in this case reviewers DO NOT have the required time to make proper comparisons, and those results serve more a catch-all.
Looking into the test setup there are two flaws with making proper comparisons in this review you have linked: theres no documentation on secondary and tertiary timings, and for testing 6200/6400 the flck was left at 2000 (see photo).
Without knowing what second and tertiary timings are, these can unfortunately have massive impacts on both latency and bandwidth of the tested kits. And when you desync fclk and mclk like this, you’re incurring an additional latency penalty on the 6200-6400 kits; the proper fclk would be 2033 and 2133 respectively.
Again some of this is beyond the scope of a typical review, but you cannot draw a conclusion (such as yours) when multiple variables are changing between kits aside from solely changing the frequency (whether they’re intentional or not).
So to reiterate, application dependent, there are benefits to ram frequency and additional bandwidth with dual CCD Zen 4 parts.
When purchasing a motherboard from now on,
we recommend a motherboard with 2 DIMM slots if you will only be installing 2 pieces of memory.
DDR5-8000+ can often be run on a 6-layer board with 2 slots.
If you have a 6-layer board with 4 slots, you may not be able to run DDR5-8200+. (Same for Intel systems)
*This may not always be possible due to individual differences in CPU and M/B.
*Some 4Layer M/Bs are not suitable for high clocks.
-- manual overclocking for DDR5-5600 1.1v Hynix A-die 16GBx2 (Green PCB).
If you want to OC up to DDR5-8000+, please install a heat sink.
If DDR5-7800 or lower, it can also be executed with Hynix M-die.
AM5 tier list
docs.google.com/spreadsheets/d/1NQHkDEcgDPm34Mns3C93K6SJoBnua-x9O-y_6hv8sPs/edit#gid=513674149
For example, with a 6-phase VRM switching frequency of 800KHz and an 8-phase VRM switching frequency of 400KHz,
the latter has inferior transient response, so the ranking is meaningless.
VRM switching frequency setting in BIOS affects the stability of CPU/iGPU CurveOptimizer.
M/Bs whose settings cannot be changed are inferior even with the same VRM configuration.
*When stability is more important than conversion efficiency