Originally Posted by rdr09
I am not assuming. The size of the flash memory chipset is the reason AMD gave why older chipsets cannot be supported.
It is just weird how in one end they are quick to admit that there is something wrong with this driver or that hardware, then on the other end cannot clarify in a more transparent way why the promise support for AM4 to 2020 has suddenly been broken.
Myself and others gave suggestions to other builders to use older chipsets, which are cheaper based on that promise.
They chose to use the NOR size card, but thats not the only reason.
Few potential other reasons:
Differences between the different chipset families.
300 and 400-series chipsets are entirely different compared to X570 in terms of the design and the code required to run them.
300 and 400-series (Promontory and Promontory LP) chipsets were made by ASMedia and they were practically PCIe to multi-IO extenders, with limited additional functionality.
Meanwhile the X570 (Bixby) is made by AMD, by repurposing the Zen 2 IOD design. The X570 is much more advanced than its predecessors and it also requires significantly heavier software infra to work.
Limiting the chipset support might boil down to something as simple as hardened security (CPU to Chipset PSP, etc) or something similar, which cannot be supported one the older chipsets.
Fairness towards the ODMs and the use of resources.
When Ryzen launched back in 2017 the ODMs did not expect to be expected to provide support their X370 (and B350) motherboards until 2020, despite the longevity of AM4 socket was known.
Had they known, the motherboards would have been significantly more expensive than they were, to amortize the lost sales and the cost of keeping the old boards supported in terms of the compability with the new CPUs.
So every time the CPUs stay compatible with the previous gen. motherboards it has a negative effect financially not only to the ODM, but on AMD as well. In addition to that, it tends to have at least a minor negative effect on the current gen. platform stability and / or overall functionality as well.
What happens is that the ODM will lose new motherboard sales due to the platform compability and in addition to that, they have to pour their very limited resources in supporting the previous gen. platforms which usually have even more problems and therefore require even more work than the current gen. ones.
So when the bios engineers (who already are stretched so thin that you can see through them) have to spend their time on the previous gen. products as well, it starts affecting stability of the current gen. products as well. To get some idea of what kind of a workload the bios engineers are dealing with, typically
a single engineer has to take care of 10+ motherboard SKUs (that was the situation at least at the time of X570 launch). And people who think that the job of a bios engineer is similar to what the community does with their own modding tools... they're mistaken and sadly so. While its true that both AMD and Intel
provide almost all of the low-level code to the ODMs that is basically ready to be "injected" the majority of a bios as you know it consists of much more than that (ODM specific code).
- Q: So why won't the ODMs hire more bios engineers then?
- A: Not with those margins they don't.
- Q: So why have they been supporting the newer gen. CPUs until now, is AMD forcing their hand?
- A: No AMD wouldn't and probably even couldn't do that. The customers do. Imagine if a major ODM would simply state that they choose not to support newer gen. CPUs even if they technically could. They would get bad rep so far up their tail that they could taste it.
In my opinion, this was absolutely the right call despite it'll leave a sour taste in the mouths of many people.
In my books, 300-series board owners have already received more than they paid for, three sittings worth.
For those who purchased a high-end X470 board or a refreshed B450 board I do have to feel for, especially when most people thought (and quite rightly so) that there is an existing upgrade path after Zen 2 as well.