New system, AM4 or AM5?

[Dirk Broer]

When you want to build a new cruncher you are currently faced with the choice to go for the trusted, proven and cheaper AM4 platform vs the new, unproven and expensive AM5.
Or, when you have plenty of cash, you might consider a choice between the trusted, proven and expensive WRX40 platform vs the completely new, totally unproven and very expensive TR5.

Boy oh boy, what to choose? Remember we're only in it for the crunching, so RGB does not come into our considerations. We want solid performance, some overclock potential, steady VRMs and M.2 NVMe slots with PCI-e 4.0 x4 -at least. And plenty of fan headers, too.

So: out go the A520 and (most of the) A620 boards, as they offer 'only' M.2 NVMe slots with PCI-e 3.0 x4 -and sometimes even PCI-e 3.0 x2. The 'A' chipsets can't be overclocked either, and generally have lesser quality VRMs.

The 600 series of chipsets differ from the 500 (B550 and X570) series as they fall apart in four: B650, B650E, X570 and X570E.
The E or "Extreme" branding is a guarantee that PCIe 5.0 is supported on both the motherboard's graphics slot and NVMe slots. E models provide access to all 24 PCIe 5.0 lanes from the processor. Non-E models only support 8 PCIe 5.0 lanes on NVMe slots while the rest of the lanes on graphics slots are dropped to PCIe 4.0. That's nice to know, isn't it?

To be continued/upgraded....

[plonk420]

i'd almost lean towards AM5. CPUs are finally competitive in price. there's a mobo or two that's not stupid expensive if you don't care about slots or USB ports (B650 HDV/m.2 whatever good. A620 HDV/m.2 bad, tho). and probably can't be a *bad* thing to at least HAVE AVX512. and it's nice not to need a dGPU (or to have to mess with one if you're running headless and it suddenly decides to not fully boot into the OS). and then there's always ECO mode. give up a few percent in performance, gain looooots of efficiency ��

the only concern is DDR5, tho if you're not building a farm of them, it's not TOOOO bad. not as bad as the DDR4 shortage soon after its launch ��

and i'm hoping/looking forward to Hardware Unboxed reviewing more A620 boards!

[Dirk Broer]

i'd almost lean towards AM5.

Some points to think over in the case for AM4 -at the present moment.
Schermafbeelding 2023-05-05 114839.jpg
and support for my thoughts byChristopher Barnatt from explainingcomputers.com

[Dirk Broer]

AM5 on the cheap, one year later:

For a cheap cruncher we only need a Mobo, a CPU/APU, a M.2 SSD and some DDR5 (I prefer at least 4GB per thread, so at least 24GB in case of the six-core CPUs that are the budget choice, while more is better.)

So an A620 board, preferably with four ram-slots and decent VRM-cooling. While A620 boards may be limited to 65W tdp CPUs, but so are budget (around 180 Euro's) AM5 CPUs, like
the AMD Ryzen 5 8500G (with IGP, Boxed),
the AMD Ryzen 5 7500F (without IGP, Tray) and
the AMD Ryzen 5 7600 (with minimal IGP, Boxed).

Below 100 Euro's/US Dollars no motherboard brand offers any VRM cooling, and the cheapest board that I like appears to be the Asrock A620M Pro RS, at some 117 Euro's, YMMV.
The WiFi version comes at 130 Euro's, but I get fiber (at 400Gb/s instead of 20Gb/s download now -upload is even 400Gb/s instead of 1Gb/s now) soon so why bother with WiFi. I love Cat 7 cables.
ASUS fans might want the ASUS TUF Gaming A620-Pro WiFi, an ATX board at some 170 Euro's, but for that price you can actually already buy a decent B650 mobo.

32GB Corsair Vengeance CMK32GX5M2B5200C40 comes at a little short of 100 Euro's

A WD Blue SN580 1TB may not be the fastest SSD your money can buy, at some 67 Euro it is the cheapest 1 TB PCIe 4.0 x4 drive you can buy, and it runs pretty cheap too: 0.065Watt for both reading and writing -a fast Samsung 990 Pro needs 5,4Watt to do so, almost 100 times as much.

Thus:
180 CPU
117 Mobo
100 RAM
67 SSD
----+
464

and now consider that choice compared to the price of an AM4 Ryzen 9 5950X as an upgrade in your present AM4 system...

[vaughan]

I would go for the extra cache offered by an X3D style CPU

[Dirk Broer]

As Vaughan just gave another reason to prefer an upgrade of an existing AM4 system over a new AM5-based on an A620 chipset, let's dive a level deeper.

As you can only spend your money once, let's make it worthwhile. An existing AM4 system can be upgraded to take a new AM4 AMD Ryzen 9 or AMD Ryzen 7 X3D CPU, 32 to 64 GB additional DDR4 RAM and e.g. a new RTX 3500 (or better) at the price of a basic AM5 system based upon a A620 chipset. This is mainly because in the latter case you need to buy a new mobo too, and all your new DDR5 RAM.

But when money is no objection, AM5 is the way to go now, consumer system-wise!

The AMD Ryzen 9 7950X3D combines both Vaughan's and mine preferences: a huge X3D cache and 16 cores/32 threads for SRBase and PrimeGrid. This needs 128GB of DDR5 if you want 4GB per thread.
And if we want all the goodies of the AM5 platform, we need the B650E or preferably the X670E chipset boards to make use of PCIe 5.0 for both the GPU(s) and the M.2 SSDs.

If and when even 32 thread CPUs are not enough -e.g. in case you might want to crunch the 64- or 128-thread Yoyo WUs- there's the sTR5 platform for the latest Threadripppers (up to 64 cores/128threads) or the SP5 platform for the latest EPYCs (up to 128 cores/256 threads)