Here’s a summary.
Ryzen 5 9600X: 6 Zen 5 cores, 32 MB L3 cache, 65W TDP, available Aug 8
Ryzen 7 9700X: 8 Zen 5 cores, 32 MB L3 cache, 65W TDP, available Aug 8
Ryzen 9 9900X: 12 Zen 5 cores, 64 MB L3 cache, 120W TDP, available Aug 15
Ryzen 9 9950X: 16 Zen 5 cores, 64 MB L3 cache, 170W TDP, available Aug 15
All models support dual-channel DDR5, the speed is DDR5-5600 when 2 modules are installed, DDR5-3600 when 4 modules are installed. They all support ECC memory, with the caveat that it requires motherboard support.
Ryzen 5 9600X: 6 Zen 5 cores, 32 MB L3 cache, 65W TDP, available Aug 8
Ryzen 7 9700X: 8 Zen 5 cores, 32 MB L3 cache, 65W TDP, available Aug 8
Ryzen 9 9900X: 12 Zen 5 cores, 64 MB L3 cache, 120W TDP, available Aug 15
Ryzen 9 9950X: 16 Zen 5 cores, 64 MB L3 cache, 170W TDP, available Aug 15
All models support dual-channel DDR5, the speed is DDR5-5600 when 2 modules are installed, DDR5-3600 when 4 modules are installed. They all support ECC memory, with the caveat that it requires motherboard support.