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[Discussion] Hypercache question
Posted: 27 Jul 2025, 06:26
by luismartin
Maybe this is a stupid question, but does enabling Hypercache on an SSD actually do anything?
I'm speaking from experience, because I don't notice any difference between having it enabled or not, and I've read that Hypercache often causes problems.
If the answer is I have no difference, I shouldn't enable it, I've already done that, but I'd like to know if enabling that type of cache is actually useful, Or when hypercache is necessary and actually works.
Re: [Discussion] Hypercache question
Posted: 27 Jul 2025, 11:30
by TMlinda
Maybe you can read the introduction of this feature to answer some of your confusion:
viewtopic.php?t=4789
Re: [Discussion] Hypercache question
Posted: 27 Jul 2025, 18:39
by luismartin
Thanks, I'd already read that.
Perhaps in my case, with a 220TB RAID5 and using the NAS with Emby, it's more of a placebo issue because I haven't noticed any difference between having Hypercache enabled or not.
It's even worse because sometimes when the NAS boots up, the disks are active for over two hours, if I have Hypercache enabled.
Anyway, thanks again for your support.
Re: [Discussion] Hypercache question
Posted: 27 Jul 2025, 19:53
by Gremlin
luismartin wrote: ↑27 Jul 2025, 18:39
if I have Hypercache enabled.
What mode of Hypercache and which TOS version (there were some changes, apparently, in 6.0.694.
Re: [Discussion] Hypercache question
Posted: 27 Jul 2025, 21:25
by TMlinda
The disk is active when data is being written back to the disk via the SSD.
Re: [Discussion] Hypercache question
Posted: 27 Jul 2025, 21:43
by luismartin
What mode of Hypercache and which TOS version (there were some changes, apparently, in 6.0.694.
[/quote]
The Hypercache I had enabled was Balanced mode. (I was afraid to use the other mode due to data loss or corruption, which happened to me a year ago.)
The TOS version is 6.0.694
Re: [Discussion] Hypercache question
Posted: 27 Jul 2025, 23:25
by luismartin
The only change with TOS 6 is that before there were 3 cache modes to choose from, now there are only two.
Re: [Discussion] Hypercache question
Posted: 28 Jul 2025, 00:24
by Gremlin
From the Support Help Page:
How is SSD Cache Capacity Calculated?
The minimum value among the following three is taken:
The capacity of the disk used as the SSD cache.
The capacity of the target volume for which the SSD cache is being created.
The maximum cache capacity allowed by the system memory = (Total system memory {G} x 0.6 - Used system memory {G}) * 1024 / 5.5 .

(TOS 6.0.694 and later versions have removed this restriction)
Re: [Discussion] Hypercache question
Posted: 28 Jul 2025, 21:12
by luismartin
Thanks everyone for the replies, but it doesn't clarify why I don't notice a speed difference between using Hypercache and not.
In my case, it doesn't help, and I forget about using Hypercache.
Re: [Discussion] Hypercache question
Posted: 29 Jul 2025, 19:54
by TMzethar
If the network card bandwidth is significantly lower than the SSD speed, Hyper Cache primarily focuses on 4K random read/write operations, enabling faster speeds when transferring small files.