15K HDD implementation through RAID

[Topweasel]

When I quickly compare these two:

http://www.newegg.com/Product/Produc...82E16820167095

http://www.newegg.com/Product/Produc...82E16822332062

Practically the speeds will be similar and SSD is cheaper per GB compared to 15K... So isn,t it a better choice to implement SSD RAID 5 instead of 15K RAID 5???

Yes but you have to be careful. As it is most SSD's have great performance because of Windows 7 and TRIM. It levels the playing field. In RAID or with most other OS's, it becomes a question of how well they designed the garbage collector. If you get a more Professional or enterprise target drive, you usually end up with a pretty good GC. If you can the best performance and GC is probably the Intel 520 series. But that comes at a pretty decent cost per GB.

 

[uzuncakmak]

Now I know that this is has been taken care of. Keep in mind the read speeds of the drives. If you look at Newegg, you can see the difference in read speeds of almost any drive. As far as I know there isn't a single 2 drive Raid 0 configuration that would even with SAS drives, read as fast as one decent SSD.

So if after teaming you still one day decide to look back at changing the drives. Keep in mind SSD. Performance issues can arise from 2 issues WinXP/Vista, or Raiding them. Both are solved by making sure you get one with a really good Garbage Collector.

When I check reading rates SSD is winner.. with RAID 5 I will have parity drive, but still dont know who to listen as some say 15k drives and some SSD :S

 

[uzuncakmak]

Yes but you have to be careful. As it is most SSD's have great performance because of Windows 7 and TRIM. It levels the playing field. In RAID or with most other OS's, it becomes a question of how well they designed the garbage collector. If you get a more Professional or enterprise target drive, you usually end up with a pretty good GC. If you can the best performance and GC is probably the Intel 520 series. But that comes at a pretty decent cost per GB.

what is a garbage collector??? lol when u first mentioned garbage collector I was thinking of throwing them away or something like that..

 

[Topweasel]

When I check reading rates SSD is winner.. with RAID 5 I will have parity drive, but still dont know who to listen as some say 15k drives and some SSD :S

You can't just say SSD and RAID without people worrying. Just like you still have people benchmarking their SSD's every day, worried that TRIM isn't working. SSD's back in the day were finicky and lost performance quickly. Some needed to wiped within months, to get its speed back. Eventually manufacturers started really working with their Garbage Collectors (these basically make area's that once held information to be able to be written to again), so then it became a question of which one ran the best throughout the normal and abonormal writing of information to a drive. Then came Trim to Win7. Windows basically does the heavy lifting for the GC. RAIDing means going back to late 2010 with you wondering how your drive is going to work 8 months from now.

So again once you throw in RAIDing a lot of people default to RAID + SSD equals bad. And either Recommend you get 1 drive, or 2 HDD's.

But again doesn't matter if you get a drive with a good GC. Specially if read speed is the biggest worry. None of this matters if information on the drives rarely changes.

 

[Topweasel]

what is a garbage collector??? lol when u first mentioned garbage collector I was thinking of throwing them away or something like that..

Think of a recycle bin of your computer you delete the file but its not really gone yet. When you delete information from the drive, it clears the information out, but the actual sectors on the drive still contain the 1's and 0's. A garbage collector basically takes sectors cleans it out (resets the data) and tells the controller that it can now write to the sector. Much like a Garbage truck would come by and empty your bin and then set them back for you to refill. TRIM basically does a lot of what GC does, just is sent from the OS and does it all the time specially when you delete a file.

Which means when looking for drives if you have Windows 7 and are not raiding them, then you only ever need to worry about read and write speeds. Running RAID or not on Windows 7 you have to read reviews like Anandtechs to see what the drive looks like without trim and what its like if you make it difficult for the Garbage Collector to get some idle time.

 

[DominionSeraph]

So if after teaming you still one day decide to look back at changing the drives. Keep in mind SSD. Performance issues can arise from 2 issues WinXP/Vista, or Raiding them. Both are solved by making sure you get one with a really good Garbage Collector.

Except for the "performance issues" of bluescreening and random bricking...

"astronomical"?.. lol. There are so many things wrong with those statements that it's not even worth going into it with you.

IOW, "I am so far from having any idea what I'm talking about that I can't even begin to put into words why it is I believe the ridiculous nonsense I believe, and so I can't begin to counter you."

15k SAS will destroy a desktop drive in a multiuser environment.

When I check reading rates SSD is winner.. with RAID 5 I will have parity drive, but still dont know who to listen as some say 15k drives and some SSD :S

How robust is your backup solution?
SSD will be the performance winner. The problem is reliability.

 

[uzuncakmak]

Think of a recycle bin of your computer you delete the file but its not really gone yet. When you delete information from the drive, it clears the information out, but the actual sectors on the drive still contain the 1's and 0's. A garbage collector basically takes sectors cleans it out (resets the data) and tells the controller that it can now write to the sector. Much like a Garbage truck would come by and empty your bin and then set them back for you to refill. TRIM basically does a lot of what GC does, just is sent from the OS and does it all the time specially when you delete a file.

Which means when looking for drives if you have Windows 7 and are not raiding them, then you only ever need to worry about read and write speeds. Running RAID or not on Windows 7 you have to read reviews like Anandtechs to see what the drive looks like without trim and what its like if you make it difficult for the Garbage Collector to get some idle time.

In the end I understand (given that I do have win 7 machine), RAID ing SSDs I will not have MUCH to worry about?!...

 

[Edrick]

Personally, I have lost data on SSDs in the past. I love SSDs for system drives and application drives, but not for important data storage.

So yes, SSDs will be faster, but 15K HDDs are more reliable.

 

[uzuncakmak]

Except for the "performance issues" of bluescreening and random bricking...



IOW, "I am so far from having any idea what I'm talking about that I can't even begin to put into words why it is I believe the ridiculous nonsense I believe, and so I can't begin to counter you."

15k SAS will destroy a desktop drive in a multiuser environment.



How robust is your backup solution?
SSD will be the performance winner. The problem is reliability.

I see your point.

I can then use SSD for my desktop performance and use 15K drives for network feed. If this is a good idea and applicable, then how? on the same array?!!

Can you also name a few good 15K drives between 160-300 GB?

 

[rsutoratosu]

Enterprise ssd raid are more reliable, else emc wouldn't make them and sell them.
They have no problem with raiding ssd and losing speed.

EMC's 400gb ssd is around 23k each, gives you an nice 6000 iops per disk vs 175 on a 15k. 7200 sata are rated 75 IOPS/disk , 10k @ 125 IOPS/disk.

If you want speed on 15k look into nested raid aka raid 100. Speed comes with cost

 

[Topweasel]

In the end I understand (given that I do have win 7 machine), RAID ing SSDs I will not have MUCH to worry about?!...

Correct and both Edrick and Dominion are right, SSD's today not named OCZ or use a Sandforce chip, are much closer to being truly consumer ready then ever before. But honestly until most of this generation have been up and running for a couple years its going to be hard to get past the terrible history they built up in 2009 and 2010 especially. Even then you still have a handful of manufacturers that while better then OCZ, are still putting out drives that have plenty of bugs.

That said I think that we are pretty close to being as good or reliable, if not already past it in comparison to spindle based drives. But then again I am not dealing with information I can't loose and have a backup solution for the stuff I am kind of worried about. It's a judgement call and its really a line in the sand. Some people will think its there, and others will think they have a lot to prove and it will be a while before we see which is right.

As for the drives if your going to go 15k for the data no reason to get an additional SSD for the main drive.

 

[Smoblikat]

Have you considered using an SSD? Performance wise, that would make the most sense. A good 512 GB SSD will be pricey, but then so are SAS 15K RPM drives. And the SSD will be much faster still.

If no SSD, the 2x 15K Raid 0 will be the fastest. raid with only one disk is not possible

Well its possible but virtually useless. Partition and software RAID the partitions .

@OP Use 2X15K RAID1, its double the read, plus redundancy. People seem to forget that RAID1 doubles your reading speed, just not your write.

 

[uzuncakmak]

Well its possible but virtually useless. Partition and software RAID the partitions .

@OP Use 2X15K RAID1, its double the read, plus redundancy. People seem to forget that RAID1 doubles your reading speed, just not your write.

What brands do you suggest to buy then for 15K in RAID 1?