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Average dd speed for single 5400 RPM drive?
Just wondering what the Average dd speed will be for a single 5400 RPM drive?
Any idea how much difference going from 5400 to 7200 would be?
Is more details needed to give a meaningful reply?
Here's the test I'm running:
ree@ubuntu:~$ dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 36.0168 s, 29.8 MB/s
Comments
Your test should be about 35 percent slower than a 7200rpm drive. That's a rough estimate and also depends on the type of drive, how much cache, etc.
30-60 for 2.5 inch drive, 50-90 for 3.5 inch drive from what I remember, I tested a load a while back.
30MB/sec is typical for a single 5400rpm. About 60MB is normal for good 7200 rpms.
i see about 90MB/Sec from my Samsung hm250hi
Can go a lot higher these days. Depends on the type of drive - optimized for latency / smaller files or for sequential.
Most modern 7200 drives I see are more like 90-120 with the "dd test".
+1
those Seagate Barracuda Drives will see 180MB/Sec easy though. but don't last long.
Depends largely on platter density, cache, not so much.
Eg a drive with 2x 500GB platters will have better sequential speed than 3x 333GB (assuming same RPM).
As such, larger drives are generally faster in this department.
If this is on your Delimiter blade server then you need to enable the RAID controller's cache. Without it disk performance is really sucky, its a 'feature' of HP's RAID controllers.
Delimiter will be able to assist you in enabling it.
Maybe yours is a little bit slow, this is an atom netbook:
Thanks guys, good to know it's not out of the ordinary. When I first saw it I thought it seemed really low, but then after getting the model number and seeing that it was a 5400RPM notebook drive, I wasn't so sure if it was low or normal.
@MarkTurner Yeah using hpssacli I saw that the write cache was disabled, but I also saw it's not battery backed so it doesn't seem too safe to enable it. For shits and giggles I enabled it long enough to do a comparison test, and it's up to 105MB/s with it enabled.
So yeah, definitely an improvement, but not sure how wise it is without the battery. I've had the server unexpectedly power down in the past, but that was during the time when they were doing electrical upgrades, so maybe it was just a one-off. Not sure I'd want to risk my data by hoping it was a one-off though
@Ree - You have two options:
Which did you enable?
PM me your controller config and I'll check it.
Ahh, I see now I enabled the drive write cache, but you recommended enabling the controller cache. I haven't been able to do that, and from what I'm reading it may be due to there not being a battery on the raid card. Here's what I'm using to enable it (or at least try to enable it):
sudo hpssacli ctrl slot=0 modify nobatterywritecache=enable
But that doesn't change the status of the config:
I thought you had one of the larger systems, this looks like an E200i controller on a X5150. In that case I'd just enable the drive cache:
hpacucli ctrl slot=0 modify dwc=enable
Don't enable the RAID controller cache without battery backup, its a recipe for extreme pain.
Yeah, X5150. I passed on the first round of "pay $100 to upgrade the processor to an L5420", but when the second batch of 70 became available I upgraded. So I guess this all may be moot since my HD will be moving to a new server in the next week or so, and presumably there'll be a different raid controller on it.
@MarkTurner any idea if I can ship my own SSD drives to Delimiter and use them instead of renting theirs (which seem insanely expensive!)
(asked billing, but they won't get it until later tomorrow sometime and thought you might know)
Edit: nm, I guess I opened the ticket in dedicated support not billing, and they replied while I was posting this. Apparently its a no on mixing own hardware with dedis...
@Ree - Assuming they could get it approved, we would require the liability insurance as we do for colo customers and that will cost you more than their HDD rates. I expect the premium would be upwards of $200/month
What would the liability insurance be for? Not that it matters since they said no, just curious.
Really sucks that a new 850 pro can be bought for $100, and thats what they charge per month for an 840 pro. Quite the profit on that upsell!
Any customer equipment has to be covered with a liability insurance, even a hard disk because if it gets determined it was the cause of a fire/disturbance then there needs to be a path to recourse against.
What size SSD are you trying to get? Pricing is nothing like that for a small one. Maybe 1TB unit. PM me the details, I get that sorted for you.
Too slow. I replaced all my 2.5" HDDs with SSDs and now everything is so beautifully fast.
Also, Windows seems to cause much more hard drive load than Linux (Ubuntu) as far as I remember. I tried to look at RAM caching, but in the end a SSD was the easy way out.
Ahh, makes sense.
The only option on the X5150 is the 128GB 840 pro, which is $80 to upgrade to on the first drive and $100 to add a second. Ill pm in a minute, battery is dying so I need to find a charger.
@Ree - You can replace the 500GB HDD for Samsung 840 Pro 120GB for $10/month and a second one for $20/month
@MarkTurner is it normal to have speeds of 8 MB/s if I turn the cache off....
@ronaldgrn - Of course not, without the cache enabled I'd expect 20-30MB
[root@gaia ~]# hpacucli ctrl slot=0 modify dwc=disable [root@gaia ~]# dd if=/dev/zero of=sb-io-test bs=1M count=1k conv=fdatasync 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 117.423 s, 9.1 MB/sI got higher this time >.<
@ronaldgrn: and what do you get with the DWC enabled?
80 MB/s ... so not really complaining XD
I got 7.5MB/s with your parameters. What do you get with bs=64k count=16k? That's what I was using when I got my 30MB/s results.
With dwc=enable I get 56.7MB/s with your parameters.
Retry with block size of 64k
@Ree with bs=64k count=16k still get 9 MB/s. but meh, as long as its quick with the cache im good