Decreased speed with PrimoCache task

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dondolarson
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Decreased speed with PrimoCache task

Post by dondolarson »

I've been testing the latest PrimoCache about the whole trial period, and it looks like I'm getting better performance without this software. Can someone explain to me what's wrong? I don't believe it should look like that.

This is how it looks when the PrimoCache task is paused:
HDD.jpg
HDD.jpg (58.92 KiB) Viewed 3304 times
This is how it looks when the PrimoCache task is running:
PrimoCache.jpg
PrimoCache.jpg (58.98 KiB) Viewed 3304 times
I'm trying to accelerate a 1,3TB partition of my Toshiba P300 3TB hard drive with an Intel 545s 256GB SSD.
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Re: Decreased speed with PrimoCache task

Post by Support »

By default, PrimoCache set the cache poliy to "100% read" for level-2 cache. That is, level-2 cache only cache read-write and ignore write-data. This is best policy for most real scenarios. However, this default setting will show no performance boost in benchmark testings. If you want to check the benchmark performance in tools like CrystalDiskMark, you need to allow L2 cache to cache write-data. Follow steps below to enable it.
1) In the cache configuration dialog, click the icon button "Advanced L2 Cache Options",
2) Uncheck the option "Individual Read/Write Cache Space".
3) Click OK to apply the change.
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dondolarson
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Re: Decreased speed with PrimoCache task

Post by dondolarson »

If it will not show any performance gains in benchmarks, why it decreased in benchmarks then? I can't tell the real performance is better though. Imo it's decreased too but need more time to check it.
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Re: Decreased speed with PrimoCache task

Post by Jaga »

dondolarson wrote: Sun Sep 20, 2020 8:46 am If it will not show any performance gains in benchmarks, why it decreased in benchmarks then?
Overhead.

dondolarson wrote: Sun Sep 20, 2020 8:46 amImo it's decreased too but need more time to check it.
Using a properly configured L2 on a decent SSD will always give better performance than a spinner drive. No testing necessary. I'd suggest enabling write caching on your L2 since it is large enough to handle it, unless you do large downloads to that drive (i.e. movies). If the cached drive has game installs on it, the performance on them will improve the more you use them while caching is enabled.
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dondolarson
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Re: Decreased speed with PrimoCache task

Post by dondolarson »

It's a "my files" partition loaded with documents, pictures, music, a lot of application .exe install files and game image .iso files, NO movies. 90% of all "single" file on this partition is below 100MB, game images are the only "big" files on this partition but I'm using them a couple of times in a year.

I'm gonna swap the Intel 545s 256GB SSD to a Samsung 860 EVO 500GB SSD later this year, for caching only, and buy a 1TB M2 NVME or SATA SSD drive for system partition and installed games. Then my plans are to RAID0 both of my current Toshiba P300 3TB drives, split into a couple of partitions to sort and separate bigger files like movies and other "big" media from all "smaller" like "my files" frequently used files, and buy a 6GB drive for backup only.

In addition to the L2 cache which is accelerating some partitions on an HDD, I'm using 14 of 32GB RAM as a L1 cache for the system partition on a SSD. Should the L1 cache for the system be so big or may/should I shrink it a bit, and split RAM between all accelerated HDD drives, even if they only gonna get like 1-4GB of RAM, per partition? Looking at the stats of PrimoCache, L1 free space for system caching is shrinking hell fast. It took about 15-20 minutes to write this post and free RAM space went from 14 to 13.74GB. It goes down to 32MB just in 1 day, and never see it's 14GB free again. Does the system SSD partition need an acceleration of L2 cache for flushing data onto it too? Should i give L2 cache even for the system/SSD?

Also, I was thinking of upgrading to 64GB RAM later this year, if I get a good Black Friyay discount on them (or buy used ones and sell my 4x8GB sticks), and use 38GB for caching, but only if I'm gonna benefit this on my system, and I'm not sure about that, not yet. May you help me? I'm not a paid user, not yet. I just need to prepare for everything and see that everything works the way it should.
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Re: Decreased speed with PrimoCache task

Post by Jaga »

I have 64GB of RAM installed here, and it works beautifully with high-use apps and Primocache (a 34GB L1 does nicely on the system/app drive). So yes, I'd recommend that configuration if you can afford it and want your hit rate with Primocache to increase.

Sounds like the larger SSD would be a good choice too, if you're going to combine data drives. However I'm not sure I'd put them in a RAID 0 config, since it doubles the failure rate of the entire volume. Instead I'd use the same solution I have here on my server, which is software called Stablebit Drivepool. It will combine the drives without using realtime parity and present them as a larger single volume. You can set redundancy on specific folders (or folder trees) if you want, and add/remove drives to scale it larger/smaller as you need. If you really want parity on the underlying drives (I have dual parity here on 9 drives) you can use Snapraid to accomplish that, which is free.
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Re: Decreased speed with PrimoCache task

Post by dondolarson »

Jaga wrote: Mon Sep 21, 2020 11:41 pm I have 64GB of RAM installed here, and it works beautifully with high-use apps and Primocache (a 34GB L1 does nicely on the system/app drive). So yes, I'd recommend that configuration if you can afford it and want your hit rate with Primocache to increase.

Sounds like the larger SSD would be a good choice too, if you're going to combine data drives. However I'm not sure I'd put them in a RAID 0 config, since it doubles the failure rate of the entire volume. Instead I'd use the same solution I have here on my server, which is software called Stablebit Drivepool. It will combine the drives without using realtime parity and present them as a larger single volume. You can set redundancy on specific folders (or folder trees) if you want, and add/remove drives to scale it larger/smaller as you need. If you really want parity on the underlying drives (I have dual parity here on 9 drives) you can use Snapraid to accomplish that, which is free.
You must have misunderstand me as I won't put any SSD into RAID... but let's start it once again.

I wasn't thinking of giving all available 38 out of 64GB RAM for 1TB system/games SSD drive only, unless it's not worth giving RAM to 2 HDD partitions (on the 2x 3TB HDD drives in RAID0) - max 10-12 out of 38GB RAM for both HDD partitions, so max 26GB RAM can go for the SSD system/games on a 1TB SSD, if so. If that matter for properly configured PrimoCache and cache working, the first HDD partition is filled with "my files" data as told before in this thread and it's 2,4TB big, and then another partition with HDD installed games on it which is 706GB.

Beside of the available 38GB L1 RAM cache, there's also gonna be a 500GB Samsung 860 EVO SSD for caching purposes only, but the question now is, if L2 cache should only be configured to accelerate both HDD partitions, or maybe for accelerating another SSD too? I was reading couple of threads on this forum, and people generally don't advice to L2 accelerate an another SSD.
If they're right and there is 0 L2 cache for a SSD, and with the RAM flush every restart, "prefetch last cache" and "start at windows boot" ticked, where's the L1 cache from an SSD stored then huh?

I don't care about any failure rate. I'm 30 years old, been using PC in 15 years and spent thousands of hours behind a screen, and none of the 15 hard drives I've had in my life has ever corrupted. I was running RAID0 couple of years on 2x Samsung F3 500GB drives back in times when people haven't even heard about existence of a SSD drive, and it was working nice. Beside of it and as told before, there gonna be a 6TB HDD for backup of data from every partition, so I'm safe and at most it will cost me a new hard drive and couple of hours for restoring the backup.

Your software solution overhead CPU, and it sound almost the same as Windows pool management.
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Re: Decreased speed with PrimoCache task

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dondolarson wrote: Sun Sep 20, 2020 8:46 am If it will not show any performance gains in benchmarks, why it decreased in benchmarks then? I can't tell the real performance is better though. Imo it's decreased too but need more time to check it.
Did you test them multiple times? Sometimes benchmark results vary much, especially when the speed is lower than 200MB/s. But if you use L2 to speed up HDDs, it will definitely speed up HDDs if read data is from L2 cache.
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Re: Decreased speed with PrimoCache task

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dondolarson wrote: Mon Sep 21, 2020 2:05 am It goes down to 32MB just in 1 day, and never see it's 14GB free again.
'Free Cache" just indicates how much cache space is completely free (no data cached). When you see its value is about 32MB, it means that cache space is full of data, and PrimoCache will automatically discard old cached data and cache new data. This is not a problem. In summary, when new data need to be cached, if its value > 32MB, PrimoCache uses free space to cache new data, otherwise, PrimoCache discards old cached data by certain cache replacement algorithm, making free space for caching new data.
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Re: Decreased speed with PrimoCache task

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dondolarson wrote: Mon Sep 21, 2020 2:05 am Does the system SSD partition need an acceleration of L2 cache for flushing data onto it too? Should i give L2 cache even for the system/SSD?
Usually no need, unless your L2 SSD is 2x faster than the target SSD.
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