Check if you need more RAM or an upgrade.
Check if you need more RAM or an upgrade.
You're weighing options for your HP z840 workstation upgrade. Adding more memory sticks can improve performance, but the best choice depends on your priorities. The 16GB option would likely be faster than the 8GB setup, especially with DDR4-2133 ECC or 2400 ECC. Since you mentioned you could recoup the cost by selling the old system, it might make sense to go with the higher capacity now. Consider your workload and whether speed is more important than immediate savings.
It seems the trade-off isn't worth it—16 sticks give you 2DPC, enough for rank interleaving, yet the performance gain is minimal. Instead of expanding to 192GB, consider using eight 16GB sticks for a larger capacity.
I’d opt for the quicker performance and then dispose of the old RAM. The 8x8GB with 2133MHz is actually priced close to 100 pounds here in the UK, so I’d go for the faster option and sell your old RAM now. You can get it for about 70 or 80 dollars, or even less (still around $50), because US prices for 64GB at that speed seem reasonable.
Since the goal is to minimize cost and complexity, ranking interleaving performs better without significant slowdown.
I've worked with those before. I have 18 drives—9 for each CPU and 3 for each channel—in a legacy server using DDR3-1333. They're running at 800MHz, which is fine. Appreciate the feedback!
I recently purchased 128GB RAM at a reasonable cost, and it makes sense to keep the number of sticks minimal—like one per channel. From my experience with x99 and Ryzen, adding more sticks often causes issues, such as reduced performance per channel or problems elsewhere in the pipeline.