Romex Software Forum

Hi,

Now I have a new motherboard with M.2 socket. Nice!
I plan to put an SSD drive over there and use it as L2 cache with Primocache, using a regular HDD (Seagate Barracuda 1 Tb) as main storage.
My options are:
a) 240Gb ADATA XPG GAMMIX S11 NVMe SSD (Read 3200Mb/s / Write: 1700Mb/s sequencial) (US$ 100 in my country)
b) 240Gb WD Green WDS240G2G0B SATA (R:550Mb/s / W:480Mb/s) - US$ 60

c) 120GB Corsair Force Series MP300 NVMe ( R:1520Mb/s / W:460mb/s) - US$ 60
d) 120Gb WD Green WDS120G2G0B SATA (R:550Mb/s / W:480Mb/s) - US$ 38

* Sequential Read/Write values from CrystalDiskMark.

I'm in a di(tri)lemma: size vs cost vs speed.
Questions:
* Is the higher NVMe SSD performance, as an L2 cache, perceived with Primocache with a "large" L1 cache (as 4Gb)?
* Or should I invest in a bigger, cheaper and "slower" SATA SSD?


NOTE:
My use is fairly domestic (MS Office) with some software development (Java JDK / Eclipse IDE/SVN); RAM 16Gb with 4GB of L1 cache;

Specs: CPU Ryzen 2600X, Windows 10, 16Gb DDR4 3600Mhz.

If you want to choose SSD as L2 you should answer yourself one important question - how heavy load are you expecting on your setup.

If it is going to be only short burst writes of small amount of data and mostly reading from L2 - any SSD will be enough, even the worst NAND, QLC will provide good sequential read speeds (even random will be more than OK if compared to spinning rust).
SATA3 SSD will also be good. For example, IIRC any Samsung 860 EVO has 22GB of SLC cache (regardless of capacity) so it will provide about 22GB of good write speed, then it will drop (how low it depends on mode, 500GB ~300MB/s writing directly to V-NAND TLC, 1TB and above I think it is 500MB/s).

If you expect some heavy load, then you should go with the best M.2 SSD you can find, 970 PRO, maybe even OPTANE (but that might be an overkill).

You mentioned that you are developing in JDK. Maybe the best option would be just large fast OS M.2 disk like 500GB-1TB Corsair MP510 or Samsung 970 EVO?

PrimoCache L2 cache performance depends on access speed of L2 (SSD) devices. Faster L2 device, better L2 cache performance.
You may consider factors like cost, lifespan and performance according to your scenario and choose a ssd.