Samsung 990 PRO vs Samsung 990 EVO Plus

The short answer

The Samsung 990 PRO is the better-specified drive (100/100 against 90 among NVMe SSDs) and costs about 14% more, which buys its own DRAM cache. For most people the Samsung 990 EVO Plus is the sensible buy.

• •Samsung 990 EVO Plus is cheaper at 3 of the 3 shared sizes: 10% at 1TB ($211.61 against $235.99), 4% at 2TB ($369.99 against $386.00) and 28% at 4TB ($603.67 against $839.95).
• •The Samsung 990 PRO has its own DRAM cache and the Samsung 990 EVO Plus borrows a slice of system memory instead. You will not notice on a half-empty drive doing ordinary work; you will on a drive that is nearly full or writing hard for minutes at a time.
• •The Samsung 990 EVO Plus is a PCIe 5.0 drive against PCIe 4.0 for the Samsung 990 PRO. It uses two lanes rather than four, though, so it reaches about the same speed as a full-width PCIe 4.0 drive: the newer number on the box is not a faster drive here.
• •Buy the Samsung 990 EVO Plus, best value at 4TB where it saves $236.28. Choose the Samsung 990 PRO instead for its own DRAM cache, worth the premium on a drive you will keep near full or write to hard.