SSD primary and cache

[harithaltaei]

dear all
good day

recently i purchased Thinkpad T450 with SSD 16 GB as a cache drive

i replaced the primary HDD with SSD 1 TB samsung evo

is it fine to run the cache drive + the primary SSD at the same time??

 

[bjornl]

It is fine to run the cache drive + SSD. It will work, but I wouldn't bother. The cache drive was designed to increase the performance to close to SSD levels without having to get an SSD. If you have an SSD than the boost in performance from the cache drive will be trivial and it adds complexity (another point of failure) and reduces battery run-time.

 

[harithaltaei]

It is fine to run the cache drive + SSD. It will work, but I wouldn't bother. The cache drive was designed to increase the performance to close to SSD levels without having to get an SSD. If you have an SSD than the boost in performance from the cache drive will be trivial and it adds complexity (another point of failure) and reduces battery run-time.

so its better to uninstall it ?? or use it for what?

 

[bjornl]

If it is easy to access, I'd remove it. Using an m2 drive as a cache is not a common scenario. I'd say there is little use for it. Put it on ebay?

 

[harithaltaei]

If it is easy to access, I'd remove it. Using an m2 drive as a cache is not a common scenario. I'd say there is little use for it. Put it on ebay?

thats good idea

actually the performance is good but i was wondering why can not install the expresscache!!

 

[Solandri]

Dump the 16GB cache SSD. Due to its size, it is slower than your 1 TB SSD, and using it as a cache will actually hurt performance. Let me see if I can dig up the benchmarks I got on my Thinkpad with a 16 GB cache SSD (I reconfigured it as a regular drive so I could run benchmarks on it). Here we go:

CrystalDiskMark
1000 MB
Seq: 257.1 MB/s read, 52.33 MB/s write
512k: 196.6 MB/s read, 24.66 MB/s write
4k: 17.43 MB/s read, 3.867 MB/s write
4kQ32: 0.968 MB/s read, 2.668 MB/s write

The ExpressCache software also eats up 1+ GB of RAM (it uses some RAM as a cache as well). (Edit: Please note that the above benchmarks are *really* good for a 16 GB SSD, so Lenovo is not cheaping out. But the performance still doesn't hold a candle to a real SSD.)

The Thinkpads use a 2242 M.2 card. That's 22mm x 42mm. Most M.2 SSDs are 2280 (22mm x 80mm) so will not fit. I sold that Thinkpad a year ago, but at the time the biggest 2242 M.2 SSD available was 256 GB, and it was still a lot slower than a regular 2.5" SATA3 SSD or 2280 M.2 SSD. I can't imagine the situation has improved - the smaller 2242 size just doesn't have enough space to fit a lot of flash dies, and SSDs get their speed from running 16 or more flash dies in parallel.

So uninstall the ExpressCache software. Reformat the 16 GB cache SSD as a regular drive, and use it for storage (or maybe move your pagefile to it if you're short on RAM and don't want to wear out your main SSD with too many pagefile writes). In the future if you need more space, you can replace it with a 256GB 2242 M.2 SSD, or maybe they'll have 512GB versions out by then. If you've got a friend or co-worker who bought a Thinkpad which is available with the cache SSD option, but theirs only has a HDD, you could sell it to them (and install ExpressCache to use it) to speed up their HDD performance. It's actually very effective when used with a HDD.

 

[harithaltaei]

Dump the 16GB cache SSD. Due to its size, it is slower than your 1 TB SSD, and using it as a cache will actually hurt performance. Let me see if I can dig up the benchmarks I got on my Thinkpad with a 16 GB cache SSD (I reconfigured it as a regular drive so I could run benchmarks on it). Here we go:

CrystalDiskMark
1000 MB
Seq: 257.1 MB/s read, 52.33 MB/s write
512k: 196.6 MB/s read, 24.66 MB/s write
4k: 17.43 MB/s read, 3.867 MB/s write
4kQ32: 0.968 MB/s read, 2.668 MB/s write

The ExpressCache software also eats up 1+ GB of RAM (it uses some RAM as a cache as well). (Edit: Please note that the above benchmarks are *really* good for a 16 GB SSD, so Lenovo is not cheaping out. But the performance still doesn't hold a candle to a real SSD.)

The Thinkpads use a 2242 M.2 card. That's 22mm x 42mm. Most M.2 SSDs are 2280 (22mm x 80mm) so will not fit. I sold that Thinkpad a year ago, but at the time the biggest 2242 M.2 SSD available was 256 GB, and it was still a lot slower than a regular 2.5" SATA3 SSD or 2280 M.2 SSD. I can't imagine the situation has improved - the smaller 2242 size just doesn't have enough space to fit a lot of flash dies, and SSDs get their speed from running 16 or more flash dies in parallel.

So uninstall the ExpressCache software. Reformat the 16 GB cache SSD as a regular drive, and use it for storage (or maybe move your pagefile to it if you're short on RAM and don't want to wear out your main SSD with too many pagefile writes). In the future if you need more space, you can replace it with a 256GB 2242 M.2 SSD, or maybe they'll have 512GB versions out by then. If you've got a friend or co-worker who bought a Thinkpad which is available with the cache SSD option, but theirs only has a HDD, you could sell it to them (and install ExpressCache to use it) to speed up their HDD performance. It's actually very effective when used with a HDD.

thats exactly what i was think about, thanks alot for your reply.