Terrible RAID0 Performance

[jschmok]

Hi All,

I've got myself a FreeNAS system, but this post is not relating to that system. It runs well.

I've got a question relating a standard RAID setup using a Perc 5i RAID Controller.

Specs:

Intel i7 2700k
16GB 1600Mhz RAM
OS Drive - Crucial MX500 500GB SSD
RAID Physical Drives - 4 x WD Black (2010) drives with about 2-3yrs of usage previously in a RAID5
RAID Controller - Dell Perc 5i RAID Controller w/ 128MB RAM Cache (battery is dead)

Configuration is in a screenshot attached but basically:
RAID 0 - 4 x 1TB WD Black (2010) drives
Stripe Size - 16kb
Disk Caching Disabled
No Read Ahead
Write Through


I'm getting VERRRY bad write performance on it! This card should be able to handle 300MB/sec. The drives are probably in the 90MB/sec area so 4 in a RAID0 should be able to accomplish 300 or even 200.

I'm getting Minimum 1MB/sec.... Max 7MB/sec with an average of 5.5MB/sec. Please see RAID0-2 screenshot.


What can I do to increase the performance of this RAID0 setup! I want to use it for gaming, have a couple hundred GB of games on a single HDD and want it on this RAID. Copying the files over takes FOR-EVER due to this lack of performance. Any thoughts??

 

[Redcoat]

Perhaps an obvious question, but why are you asking this here?

 

[jschmok]

I don't have any friends who are into computers to this degree..... I don't know where else to ask or who else to ask. Googling can only get you so far :( I feel lost and thought I could find someone who would be willing to help or even at least point me in the right direction.

 

[Constantin]

The drives are too old to be SMR type, which could explain some of the performance degradation?

I'd consider redoing this as a FreeNAS system and dropping the RAID controller. One less thing to fail.

 

[jschmok]

Thanks Constantin, These drives are from the same generation as the Perc 5i RAID controller so they should work within spec of each other I would've imagined.

Whats SMR by the way?

 

[hescominsoon]

your biggest problem is the perc card. you need to get an HBA instead of a raid card.

 

[Yorick]

So all this “FreeNAS it” talk: it’s a gaming machine. They’re not going to play games on a FreeNAS server. Raid0 makes sense for data that is allowed to die when a single disk dies - just replace the disk and bring the game installs back in.

As for why it’s dog slow: No idea, I have 0 experience with that controller. Could be a driver or firmware issue for all I know. Maybe try the homelab reddit, or servethehome forums? They should be less likely to suggest you play destiny 2 on FreeBSD, snicker snicker.

 

[Constantin]

Thanks Constantin, These drives are from the same generation as the Perc 5i RAID controller so they should work within spec of each other I would've imagined.

Whats SMR by the way?

If that machine is fungible, I'd consider nuking the array, testing the drives individually (to see if one of them is holding back the whole array) with something like Crystal mark or somesuch. If all the drives pass without massive SMART errors (may be the case with drives this old) then I'd consider setting up a software RAID instead and seeing how that performs. Many things could be crushing performance, including driver issues.

As for SMR, it's a relatively new recording technology now commonly used in larger drives to increase areal density and thereby lower the cost of manufacture (see here for a primer). SMR drives have been noted to suffer from some pretty horrific performance issues when used in a NAS / RAID array / etc. thanks to how the drive uses a combination of RAM, CMR sectors and finally SMR sectors to write data to disk. In many ways, these drives have adopted operating principles behind SSDs... but thanks to the inherent latency associated with spinning drives, there are some very real impacts on drive performance at times.

But older 1GB drives should likely be based on CMR technology, unless the drive is a 2.5" platter.

 

[jgreco]

Moderator note: evicted over to off-topic because this isn't really FreeNAS_related

 

[jschmok]

Hi All,

Sorry to bring a non Free-NAS topic to a FreeNAS Forum. Once again, was hoping to get some insight from a community of like minded people with differing skillsets.

@Yorick seems to have the right idea. As stated its a gaming system so FreeNAS would not be an option. If the RAID dies... who cares, I just replace a drive and reinstall games.

That being said, I did some playing around yesterday and resulted in some VERY nice numbers from the Intel Onboard motherboard RAID controller.

I've got basically SSD numbers from a RAID0 of 2010 Gen WD Black drives. My games are happy, I'm happy... Thanks again guys!

 

[HoneyBadger]

Hey @jschmok

The root of your problem with the PERC card is that you've effectively disabled all disk and controller cache with your config choices of "Disk caching disabled" and "write through" - that's why your speeds were so abysmal. But they were safe, at least.

 

[Ericloewe]

Sorry to bring a non Free-NAS topic to a FreeNAS Forum.

Note: Nothing wrong with that, we like to try to help - we just might not have much useful information to give.