PrimoCache vs Intel Optane

[Muhlis]

Do RAM cache programs like PrimoCache make PC faster than if we use Intel Optane? Are they do the same intelligent caching?

[Electronics Wizardy]

Your pc already uses all the free ram as a disk cache, so things like primo cache don't really have a point for caching.

 

Optane caching seems pretty smart, and is pretty good at caching boot files, and I haven't seem as much logic in most other caching programs.

[LogicalDrm]

-> Moved to Storage Devices

[StDragon]

On 3/2/2021 at 1:30 AM, Electronics Wizardy said:

Your pc already uses all the free ram as a disk cache, so things like primo cache don't really have a point for caching.

You must be referring to "Standby" memory in Windows 10. Basically, a shadowcopy of what was previously in use in RAM, but inactive and not needed to be purged as enough room exists to keep it there.

 

While yes, Standby memory is a form of caching to launch applications faster, it doesn't cache storage at the block level, only application level. So while previously ran applications will re-launch faster than the first time around, application such as games will still request texture mapping and other assets at the file level. It's the latter that I don't believe gets cached in "Standby". For block level storage caching, you would have to use something like Primocache.

[Electronics Wizardy]

12 minutes ago, StDragon said:

You must be referring to "Standby" memory in Windows 10. Basically, a shadowcopy of what was previously in use in RAM, but inactive and not needed to be purged as enough room exists to keep it there.

 

While yes, Standby memory is a form of caching to launch applications faster, it doesn't cache storage at the block level, only application level. So while previously ran applications will re-launch faster than the first time around, application such as games will still request texture mapping and other assets at the file level. It's the latter that I don't believe gets cached in "Standby". For block level storage caching, you would have to use something like Primocache.

WIndows disk caching will cache all files, so that included game text files, and can cache parts of a file aswell. So ram caching will speed up things like game load times if they fit in ram. Prime cache will override the sync commands, so Id stay away from it as it can lead to data loss.

[StDragon]

1 hour ago, Electronics Wizardy said:

WIndows disk caching will cache all files, so that included game text files, and can cache parts of a file aswell. So ram caching will speed up things like game load times if they fit in ram. Prime cache will override the sync commands, so Id stay away from it as it can lead to data loss.

Read-cache is harmless. But yeah, futzing about with write-back caching is a danger zone for sure.

 

As far as Windows read caching, there is the old LargeSystemCache registry key, but I'm not sure how relevant that is with Windows 10 or if there's a tangible improvement in game relaunches. Probably worth a revisit now that RAM is cheap.

[Electronics Wizardy]

34 minutes ago, StDragon said:

Read-cache is harmless. But yeah, futzing about with write-back caching is a danger zone for sure.

 

As far as Windows read caching, there is the old LargeSystemCache registry key, but I'm not sure how relevant that is with Windows 10 or if there's a tangible improvement in game relaunches. Probably worth a revisit now that RAM is cheap.

I don't think that registry key does anything. I have systems with 64+GB of ram that willhappily use 50+GB of ram as a disk cache, and really speed things up. 

 

It should speed up game load times a lot. I haven't done tests on this, but it seems like it does, and many other tests of caching show big improvements on game load times in future loads.

[Nick7]

On 3/4/2021 at 4:46 AM, Electronics Wizardy said:

WIndows disk caching will cache all files, so that included game text files, and can cache parts of a file aswell. So ram caching will speed up things like game load times if they fit in ram. Prime cache will override the sync commands, so Id stay away from it as it can lead to data loss.

Windows also does not write immediately to disk, unless required by app (sync write).

But, there's one thing about PrimoCache that is quite dangerous - defer writes can write data out of order, and in case if crash - it *will* lead to corruption, possibly silent (worst) - chkdsk passes, but data is corrupt.

So, PrimoCache is nice to speed up reads, but quite dangerous for writes.

On Linux, bcache is much better solution. More configurable, and can handle crash situations, so no data is lost.

[Electronics Wizardy]

49 minutes ago, Nick7 said:

Windows also does not write immediately to disk, unless required by app (sync write).

But, there's one thing about PrimoCache that is quite dangerous - defer writes can write data out of order, and in case if crash - it *will* lead to corruption, possibly silent (worst) - chkdsk passes, but data is corrupt.

So, PrimoCache is nice to speed up reads, but quite dangerous for writes.

On Linux, bcache is much better solution. More configurable, and can handle crash situations, so no data is lost.

Reads are basically the same on primo cache as the windows disk cache works about the same. The big difference is that primo cache overrides the direct command so progams like benchmakrs that want to go directly to disk, can and as you pointed out can lead to data loss, and causes benchmark numbers to be way higher.