Crucial Ballistix Sport LT 2400 MHz DDR4 DRAM Laptop Gaming Memory Single 8GB

Almost everyone knows about the benefits of Dual-Channel RAM but not the Dual-Rank. What’s Dual-Rank? I’ll keep it simple – it’s like 2-way multi-threading for RAM. When the memory chips on a channel are grouped into 2 groups (as opposed to 1 group for Single-Rank), which allows 2 sets of commands being issued back-to-back without delay to each group of chips. Why would this have any benefit? Well because memory spends multiple clock cycles selecting requested address locations (i.e. memory timings 16-16-16-39 means it takes at least 16 clock cycles to select a location in the memory array). So instead of idling and doing nothing for 16 clock cycles after issuing a RAM command, you can go and issue a completely different command to the 2nd group of chips on the RAM module. If you want the highest memory bandwidth you’d go with as many channels and as many ranks as you can. Dual-Channel + Dual-Rank memory provides 15-20% higher memory bandwidth vs Dual-Channel + Single-Rank memory, all else being equal. While all 16GB modules are almost certainly Dual-Rank, they are also a lot more expensive. Vast majority of 8GB DDR4 modules are Single-Rank. If you don’t need 32GB total RAM, these 8GB modules provide the best performance/$ alternative for 16GB total RAM. I replaced factory 2400 17-17-17 with these 2400 16-16-16 on my XPS 15 9560 and gained ~5GB/s memory bandwidth. By the way, 2666 model has 16-18-18-38-61 timings in 2666 and 16-16-16-39-55 timings in 2400. Your BIOS will select maximum supported clock frequency up to 2400 automatically or you can try to force it yourself from BIOS. 2666 does require XMP 2.0 profile support but also possible to set matching timings manually if your system supports that. One thing you should be aware of is that Dual-Rank memory puts additional loading strain on the memory bus and if you are aiming for highest memory clocks (like in case of AMD Ryzen fabric/cache clocks from RAM clock, and CPU performance increases across the board with higher RAM clocks), you should settle for Single-Rank as Dual-Rank may not be able to clock as high, depending on hardware/BIOS. Otherwise aiming for higher RAM clocks makes no sense and you should instead aim for shortest command cycle (memory timing * 1/clock, where DDR4 actual clock is 1/2 of advertised, for example 16 CAS * 1/(2400/2) = 13.333nS cycle time). I’d like to also point out that latency does go up a little with Dual-Rank but if you worry about latency, you should be worried about CPU cache latency instead. I should also mention that because of CPU cache, most general CPU-bound applications will not see the benefit of Dual-Rank RAM. However, if you make use of iGPU along with CPU, then 15-20% memory bandwidth advantage of Dual-Rank RAM will likely translate into 15-20% performance boost in 3D/compute applications using iGPU. So there you have it.

I bought my daughter an Acer Aspire E 15 E5-575-33BM 15.6-Inch FHD Notebook. This notebook comes with 4gb of RAM and a 1tb standard hard drive. Needless to say, the notebook was very VERY slow. Almost to a point of it not being workable. Boot time was 3-5 minutes. Once it did boot, it was painful to work on. I was about ready to just junk the computer and chalk up my expenses as “lessons learned” in buying a cheap computer.Before junking the computer, I did some investigating on if the computer could be improved. I learned that this computer can run a dual hard drive confiburation, with one being an SSD M2 drive, and that the RAM can also be upgraded. I happened to have a spare 256gb M2 SSD that I put in, and then upgraded to 16gb of this RAM.Needless to say, this gave me a completely new computer. It boots in about 30-40 seconds. There is little to no lag in working in the computer. I am completely happy with my purchase.