SCSI RAID?

[Sideswipe001]

People talk so much about IDE RAID here, I wondered if the same general findings held true for SCSI RAID as well. I know that in a server environment, RAID is very helpful, but what about a standard workstation-type environment? This would be just for photoshop/some CAD work/occasionally used for movie editing/converting (like from DVD to AVI).

Is there a more noticeable difference in SCSI RAID than in IDE?

I have a LSI Logic MegaRAID Elite 1600 SCSI RAID adapter already. Currently, I just have 1 drive hooked up to it. I'm wondering if adding a 2nd 15K Cheetah HD and putting them in RAID would make any real difference.

 

[Crusty]

In short, YES! Especially with a Hardware RAID controller like that . Wait til Shuttleteam, MichaelD, or Mechbgon (sp?) get in here, they have some pretty impressive SCSI RAID arrays.

 

[Sunner]

Originally posted by: Sideswipe001
People talk so much about IDE RAID here, I wondered if the same general findings held true for SCSI RAID as well. I know that in a server environment, RAID is very helpful, but what about a standard workstation-type environment? This would be just for photoshop/some CAD work/occasionally used for movie editing/converting (like from DVD to AVI).

Is there a more noticeable difference in SCSI RAID than in IDE?

I have a LSI Logic MegaRAID Elite 1600 SCSI RAID adapter already. Currently, I just have 1 drive hooked up to it. I'm wondering if adding a 2nd 15K Cheetah HD and putting them in RAID would make any real difference.

There are far too many factors to give you any kind of good answer.
A RAID card with half a gig of cache will help alot even without actually setting up a RAID config.
A "simple" RAID controller with no cache won't be any better than a cheapo ATA controller, aside from the fact that most any recent SCSI drive will beat any ATA drive, save for the Raptor.

 

[Carbonadium4]

I posted this a few days ago.

http://forums.anandtech.com/messageview.cfm?catid=27&threadid=1360661

 

[Oyeve]

Before I recently switched to an all IDE system on my main box I had 18 U160 10k rpm HDs. 4 in my PC and 14 in two U160 SCSI chassis. I was using a compaq Smart array 2000 (I think) with 512 cache and Dual Port U160 SCSI raid card and was running raid5 with a hot spare. Other than the NOISE this setup made, it was faster than even the fastest ATA or SATA drive is today. And this was on a P3 1ghz system. I stopped using it cuz the noise from the 18 hds plus the 10 fans in the external chassis' were deafening. The beauty of it was that Multitasking was so much better than with IDE drives. All my ATA and SATA drives are the fastest thats out right now but the IDE channels still get bogged down when I run apps that are on different drives. And this is on a P4 3.0ghz 800fsb with SATA and ATA/133 drives all with 8megs of cache on them. My scsi system never bogged down. Ahhh. I miss my scsi stuff. Still have it all to. Just collecting dust. *SNIFF*. I should get divorced so I can use my array again. .


Anyway, yes, scsi raid at raid 5 is the best of the best.

 

[Crusty]

Originally posted by: Oyeve
Before I recently switched to an all IDE system on my main box I had 18 U160 10k rpm HDs. 4 in my PC and 14 in two U160 SCSI chassis. I was using a compaq Smart array 2000 (I think) with 512 cache and Dual Port U160 SCSI raid card and was running raid5 with a hot spare. Other than the NOISE this setup made, it was faster than even the fastest ATA or SATA drive is today. And this was on a P3 1ghz system. I stopped using it cuz the noise from the 18 hds plus the 10 fans in the external chassis' were deafening. The beauty of it was that Multitasking was so much better than with IDE drives. All my ATA and SATA drives are the fastest thats out right now but the IDE channels still get bogged down when I run apps that are on different drives. And this is on a P4 3.0ghz 800fsb with SATA and ATA/133 drives all with 8megs of cache on them. My scsi system never bogged down. Ahhh. I miss my scsi stuff. Still have it all to. Just collecting dust. *SNIFF*. I should get divorced so I can use my array again. .


Anyway, yes, scsi raid at raid 5 is the best of the best.

What kind of drives? If they are Atlas 10k.3 are you interested in selling some ?

 

[Sideswipe001]

Originally posted by: Sunner

There are far too many factors to give you any kind of good answer.
A RAID card with half a gig of cache will help alot even without actually setting up a RAID config.
A "simple" RAID controller with no cache won't be any better than a cheapo ATA controller, aside from the fact that most any recent SCSI drive will beat any ATA drive, save for the Raptor.

As a side note to this, my RAID controller has 64 MB of cache, upgradable to 128. I should grab an old PC 133 128 MB stick to see if that speeds it up.

Carbonadium4, you are soooo tempting me to get that 2nd HD.

 

[bob4432]

a buddy of mine has a adaptec 29320r with 2 15k 36GB u320 drives on it. as far as moving large files, it will max out at ~130MB/s, which is the max for the pci bus. programs start instantly.

 

[Carbonadium4]

I think raid 0 + 1 may be faster than raid 5.

Basically out of the 4 drives I got, Raid 0 yields fastest read/write.. it could be the most expensive since you're wasting 50% of the drive for Mirror. You're striping first for speed then you mirror the whole thing to another set of drive. Mirroring should have low over head.. ill find out.. i got another 3-4 drive i can hook up i think.

Raid 1 + 0 might be different.

 

[Carbonadium4]

Originally posted by: Sideswipe001

Originally posted by: Sunner

There are far too many factors to give you any kind of good answer.
A RAID card with half a gig of cache will help alot even without actually setting up a RAID config.
A "simple" RAID controller with no cache won't be any better than a cheapo ATA controller, aside from the fact that most any recent SCSI drive will beat any ATA drive, save for the Raptor.

As a side note to this, my RAID controller has 64 MB of cacahe, upgradable to 128. I should grab an old PC 133 128 MB stick to see if that speeds it up.

Actually those are ecc memory i think.. do you have battery backup on that card ? I got the same card, 1 with battery and 1 w/o. They use different memory

 

[Oyeve]

What kind of drives? If they are Atlas 10k.3 are you interested in selling some ?[/quote]

They are Quantum drives, 10k and 8meg cache each. The capacity per drive is 33.6. I dont know if they are Atlas. They are SCA 80 pins and are in cages. I'll pop one out and let you know the model and if they are Atlas drives.

 

[Carbonadium4]

Carbonadium4, you are soooo tempting me to get that 2nd HD.

If you only want speed and dont care about data lost, 2nd drive in raid 0 would be nice.. but if it's storing data, I think u should get 3 more and do raid 0+1 or 2 more for raid 5

 

[Sideswipe001]

No battery backup on mine. And I *heard* you're supposed to use ECC, but the manual didn't say anything about it. In reality, the manual is very unhelpful about the type of RAM to use at all. Doesn't even tell you the max the card supports.

And yeah, I'm mostly worried about speed. I like a very very responsive computer. I backup regularly as it is, and I don't care if I had to reinstall the OS and restore my data.

 

[Carbonadium4]

the max is 128, i read it somewhere.. let me see if i can go get the link again..

 

[Oyeve]

My card had 12 rechargable batteries and needed ECC memory.

 

[Markfw]

BTW, what motherboard is that 1600 in ? I bet you are using a 32 bit slot. Going to a 64 bit slot, the performance JUMPED 4x on mine, and I don;t even have 15k U320 drives ! (just 10k 160) IDE SCSI on the right platform just freaking screams. What benches do you want ?

 

[Sideswipe001]

Any you can give.

You are right about it being in a 32 bit slot - currently my rig is a Asus PC-DL deluxe (dual xeon 2.8 ghz). I was considering a motherboard upgrade in the future though. I figured that the 32 bit slot wasn't hurting it with only 1 drive though. How many do you need before you eraly see a hit?

Basically, the point of this thread was curiosity if there was a REAL difference with SCSI RAID, since most people have agreed that IDE RAID has little (0-15%) in the way of improved speed. Does going from 1 SCSI to a 2 HD RAID 0 make a bigger difference than the 0-15%?

 

[bob4432]

Originally posted by: Sideswipe001
Any you can give.

You are right about it being in a 32 bit slot - currently my rig is a Asus PC-DL deluxe (dual xeon 2.8 ghz). I was considering a motherboard upgrade in the future though. I figured that the 32 bit slot wasn't hurting it with only 1 drive though. How many do you need before you eraly see a hit?

Basically, the point of this thread was curiosity if there was a REAL difference with SCSI RAID, since most people have agreed that IDE RAID has little (0-15%) in the way of improved speed. Does going from 1 SCSI to a 2 HD RAID 0 make a bigger difference than the 0-15%?

i would say yes, you will probably max out your 32bit slot with 2 new u160 drives, but definately will with 3

 

[bob4432]

about how much did you pay for the card? any hot deals with them?

 

[biostud]

try browsing around www.storagereview.com

 

[Sunner]

SCSI RAID by itself doesn't really provide anything that IDE RAID doesn't.
What does make a difference is that SCSI drives tend to be faster than IDE drives, and SCSI RAID controllers tend to to be better(more cache, dedicated XOR engines, cache, etc) than IDE controllers.

 

[Markfw]

Originally posted by: Sideswipe001
Any you can give.

You are right about it being in a 32 bit slot - currently my rig is a Asus PC-DL deluxe (dual xeon 2.8 ghz). I was considering a motherboard upgrade in the future though. I figured that the 32 bit slot wasn't hurting it with only 1 drive though. How many do you need before you eraly see a hit?

Basically, the point of this thread was curiosity if there was a REAL difference with SCSI RAID, since most people have agreed that IDE RAID has little (0-15%) in the way of improved speed. Does going from 1 SCSI to a 2 HD RAID 0 make a bigger difference than the 0-15%?

Well before I upgraded my motherboard I was getting 1ms average seek, but ony 60k thruput. Now I get 180k thruput WITH THE EXACT SAME DISK ARRAY AND PARTITION the only difference being a 133 mhz (only using 66 with the card, same as yours basicly) PCI-X and 64 bit slot. I haven;t had time to do extensive benchmarks, but maybe that will give you an idea of how much 32bit 33 mhz can kill the performance you paid for. I got mine for $172 on ebay, and found myself lucky. There are very few PCI-X motherboards out ther, and it will cost you, but I love the bandwidth !!

 

[MichaelD]

SCSI? Did someone say SCSI?

SCSI flat out rules. Period. EXCEPT in the Cost Per GB war...but if you're that worried about spending some money on quality stuff, you shouldn't be looking at SCSI anyway; it aint' cheap.

I work with SCSI arrays all day at work. 75% of them are the older 10K rpm models and they are loud. Put 10 of them in box with 6 high speed fans and it's deafening. Now imagine a server floor FuLL of said boxes.

I said "NOW IMAGINE A SERVER FLOOR..." You get the idea.

Now, on the flip side. I have a LSI Megaraid 1600 Elite with 128MB of onboard cache. On it, I have two 15K rpm Fujitsu MAS drives (18GB each). Raid 0 stripe, write back enabled, etc, etc. Got all my settings from SHUTTLETEAM, btw. He is the SCSI Master. *bows*

These two drives are NO LOUDER than the WD 120GB IDE drive they share the box with. When they are seeking, you can tell they are SCSI drives, but it's not the "soup can full of marbles" sound that the older 10K drives make.

Unfortunately, the card is in a 32-bit, 32MHz slot; it's choked. Soon (hopefully) I'll have the card in a proper 64-bit, 66MHz slot and set that badboy free!!

Currently, here's what the performance looks like:

This is an excellent shot, b/c it shows what I have enabled on the controller. Heh; wait until I move this array to a 64-bit slot! :evil: Before I bought the Megaraid, I had just a single MAS drive on a cheapo LSIU160 single channel card; I was getting 75MB/s reads!

Benchmarks don't tell the whole SCSI story though. Command Queuing, long a SCSI stronghold allows the controller to prioritize I/O requests. Also, I can read/write to the array while it's defragging or running a NAV scan w/almost no slowdown at all.

 

[Carbonadium4]

Originally posted by: Markfw900
BTW, what motherboard is that 1600 in ? I bet you are using a 32 bit slot. Going to a 64 bit slot, the performance JUMPED 4x on mine, and I don;t even have 15k U320 drives ! (just 10k 160) IDE SCSI on the right platform just freaking screams. What benches do you want ?

super micro p4d something.. and its 64 bit in 64 bit slots