ITs a con because all Ryzen APUs are PCIE-3.0, this means 5600G, 5700G all PCI-E3.0.....
The APU was supposdly to be a great product but AMD "castrated" it by literally halving the cache and using PCIE 3.0. On top of that, they use back Vega instead of RDNA....
Now, imagine what the APU would be like if AMD had taken a different approach. The use the same Zen3 with PCIE and full cache and drop in RDNA GPU. It would been a monster. I am find if they sell it more than the non-APU verison.
The 5000G series permits mobo manufacturers to provide a PCIe Gen3 x16 mechanical AND electrical. The 3000G and 4000G series only provide x8 electrical. This has very interesting consequences. ASRock has several mini-ITX boards where you can bifurcate the x16 into x8 + x8 or x8 + x4 + x4. PCIe Gen3 x8 enables you to use a large number of PCIe Gen3 x8 cards such as real hardware RAID cards, high-speed network cards for 10GbE, 25GbE, 40GbE or IB cards.
That makes it a potential platform for building a NAS more performant than usual. I proceeded with this exercise using a 5700g: Adaptec 8805, 8 x HGST He8 8TB SAS 12g in RAID10, Mellanox ConnectX-3 Pro(*). Results:
(*) Cards and disks bought on eBay from data center used hardware. Working system total cost: $2755, it would have cost $4275 with new hardware. CPU, mobo, memory bought new.
RAID10 / iozone -e -I -a -s 100M -r 4k -r 16k -r 512k -r 1024k -r 16384k -i 0 -i 1 -i 2
102400 4 122377 137437 138961 140013 138789 135158
102400 16 452399 514089 519291 516947 510771 502361
102400 512 4033711 4107312 4060943 4118576 4067673 4128712
102400 1024 4950240 5065548 4949498 5002943 4955952 5068298
102400 16384 6688698 6798433 6708287 6699676 6729967 6779653
Using Samba, sequential write (e.g. copy of a large file) is about 20 times faster than 1 GbE:
- Copying 1 GB file: 0.492 sec (median of 7 tests, tested with a PC that tops at 30 GbE, not 48 GbE though)
- Copying 2 GB file: 0.961 sec (ditto)
- Copying 4 GB file: 1.879 sec (ditto)
With its 8C/16T the 5700g can also do VM server over 40+ GbE and run other services.
28TB NAS over 40+ GbE for less than $3,000: perfect for a SOHO or a start-up where users and IT are the same people
PCIe Gen 4 does not mean PCIe Gen 3 has suddenly become bad.