SSD or SAS?

[Keitero]

I am wondering what should I be running on my new build when I get to it later in July. I have either an Intel X25-M 80GB SSD drive or 4x 36.7GB Fujitsu 10k SAS drives for my main OS. Both will be tied to an Adaptec 31205 SATA/SAS RAID card and will be running Vista Ultimate x64 till Windows 7 comes out. The new build will be a Core i7 920 with a Gigabyte GA-EX58-UD4P.

The machine is mostly used for gaming and photo/video editing. I also use VMware as well.

 

[GarfieldtheCat]

For me, I'd go SSD just because I wouldn't want 4 10K drives putting out heat and making noise in my PC. But that is just me. It just seems a lot easier to setup with one drive versus a 4 drive RAID array.

 

[Rifter]

depends, do you want it to be quiet or loud. Have you been in a room with some 10k drives screaming away under heavy load??? they are far from quiet.

 

[pjkenned]

I get like 750MB/s read from 8x 15k.1 Savvios in RAID5 so if you halve that (375MB/s) and subtract a bit for going 10k... you will probably see 300MB/s ish from the SAS setup. SSD of course will have slower read/write (raid 5 write on the IOP @ 800MHz on that card is in excess of 300MB/s so you won't be card limited) but lower access times. If you have the SAS setup, just keep it for the time being. Once 32nm SSD's hit current gen drives will be obsolete tech (as will current gen SAS). Another cheap option would be to buy more 36GB SAS drives since you can probably pick them up for <$30 and are basically adding 80-100MB/s read each time you add a drive in Raid 5 with that setup. I would caution that the Adaptec probably will choke before 800MB/s though so buying 8x more drives would be a complete waste. 1-4 more wouldn't be terrible.

Also, 2.5" drives aren't that hot, and not THAT noisy especially in a decent hotswap enclosure which most people doing SAS have anyway.

 

[MedicBob]

It seems a bit overkill to me, IMHO.

I would choose SAS over SSD. SAS is louder, but you have a large RAID card. What happens in a year when you want to move those drive to storage? Basically, use the SAS as storage and another RAID controller with SSD in RAID 0 for OS.

 

[Keitero]

Well I have the 4x 2.5" 10k drive running now and they are a bit loud, but only during load. They are quiet during idle.

 

[pjkenned]

I saw those drives on ebay for $20 each + a few bucks for shipping. I almost bought 4-8 just to compare to the 15k Seagate setup. Even if you got 500MB/s read and 350MB/s write on an 8 drive array that would be awesome. People that want cheap fast storage, with decent capacity could do that setup swapping a 3085 for the 31205 you are using and probably have 230GB usable storage with raid 5 in the event of failure for $320-$350 out the door.

 

[taltamir]

HDD Pro: faster sequential writes in raid0
HDD con: loud, high power consumption, high heat generation, and large.

 

[pjkenned]

Originally posted by: taltamir
HDD Pro: faster sequential writes in raid0
HDD con: loud, high power consumption, high heat generation, and large.

Pro's add faster sequential reads as that array will be over 300MB/s, which is faster than single drive SSDs.
Con's: A few points of clarification--
1. A 10k 2.5" SAS drive probably consumes ~4w at idle vs <1w for the SSD. So four drives is 16w. Meaning that even at $0.12/kwh that's <$17/ year total, subtract maybe $1 for the SSD's power consumption and this isn't exciting. BTW, most desktop PC's have very high idle rates on their drives. 3.5" 15k rpm drives consume probably 8w or more. Still, compared to CPUs/ GPUs this is negligible.
2. Heat generation - most sas drives go into hotswap enclosures that have fans built in. Remember 4 drives is 16w of power draw, so this is like needing to cool 1/10th of an overclocked Core i7, and you get a decent amount of surface area with 4x 2.5" drives.
3. 2.5" SAS drives are larger than 2.5" SSD's, and you do need more of them, however, a 4 drive array easily fits in a 1x 5.25" bay enclosure.
4. As for loud... SAS drives are louder, however most modern ones are not too bad, especially the 10k rpm / 2.5" versions. I'm pretty sure my watercooling pump or the huge Cosmos S side fan on Low speed is louder than my 8x 15k 2.5" sas drives. A good enclosure and some decent dampening go a long way here.

 

[taltamir]

1. A 10k 2.5" SAS drive probably consumes ~4w at idle vs <1w for the SSD. So four drives is 16w. Meaning that even at $0.12/kwh that's <$17/ year total, subtract maybe $1 for the SSD's power consumption and this isn't exciting. BTW, most desktop PC's have very high idle rates on their drives. 3.5" 15k rpm drives consume probably 8w or more. Still, compared to CPUs/ GPUs this is negligible.

Triple it to account for AC costs.

2. Heat generation - most sas drives go into hotswap enclosures that have fans built in. Remember 4 drives is 16w of power draw, so this is like needing to cool 1/10th of an overclocked Core i7, and you get a decent amount of surface area with 4x 2.5" drives.

Except, he is building a desktop, not a hotswap enclosure. which means his drives are not going to be cooled as well as they were designed to.

3. 2.5" SAS drives are larger than 2.5" SSD's, and you do need more of them, however, a 4 drive array easily fits in a 1x 5.25" bay enclosure.

Fitting 4 drives into a DESKTOP CASE is not going to be a walk in the park, you can do it, but it either requires buying a special enclosure (which reduces their appeal as a cheaper alternative) or it means jury rigging something yourself.

4. As for loud... SAS drives are louder, however most modern ones are not too bad, especially the 10k rpm / 2.5" versions. I'm pretty sure my watercooling pump or the huge Cosmos S side fan on Low speed is louder than my 8x 15k 2.5" sas drives. A good enclosure and some decent dampening go a long way here.

Now put four of them together. Besides, I said it was "louder" not "unacceptably loud to you personally"...

I gave pros and cons and I let him decide. Ultimate if the cons are "minor" or "unimportant" to HIM and the pros are "wonderful" then he should go for it, if the opposite is true than he shouldn't

 

[ochadd]

My vote goes to the X25. OS and app load times will be much faster. Allot less heat, noise, and chance of failures.

 

[pjkenned]

Originally posted by: Keitero
Well I have the 4x 2.5" 10k drive running now and they are a bit loud, but only during load. They are quiet during idle.

I assumed since he's living with the drives already fitment and current noise levels are not huge issues. Most people that do 4+ drive SAS just buy something like a 4x 2.5" in 1x 5.25" hotswap enclosure.

Buying new, I would go for the X25 most likely, but since the SAS is installed already, the performance difference is not going to be huge going to the X25. Big files better on the SAS, small files better on the X25. Since one of the options is installed, I think waiting a few months for 32nm would be much more cost effective.

And as for AC, it is true in a data center, not necessarily at home. Different ambient temps and rate of heat generation for the environment. Heck, I live in California, and I use my AC <30 days a year and 16w can get dissipated several times over by opening a window/door.

 

[Keitero]

As pjkenned stated, I have them already installed in a 5.25" 4-bay enclosure. My fans are louder than the drives at seek so noise is not really an issue. Also, heat wise, they do not get hot or even warm at all. I was looking into the idea of getting 3 more X25-Ms due to the speed I found when testing out one and lusting for more, but the price is way too high for me when I can get 4 or even 8 more 36GB Fujitsus for 1/3 of the price. The drives will be in RAID 5 (or 6 if I get 8 drives) so failure is not an issue for me per-say.

 

[zxc367]

how much does the sas drives cost in total?

 

[Keitero]

About 20 or so a drive.

 

[pjkenned]

Yea 10k 36gb sas drives are like $20 on ebay each. Not the best way to buy a drive, but burnin + raid 5/6 and you can get some nasty speeds. 15k drives can be had (i got mine new) for $40/ 36gb drive.

Buying 1-2 makes little sense, but the little buggers rock when you have lots of them + a good raid controller.