SSDs - State of the Product?

[timwhit]

How is the cache used exactly?

In most cases it's write cache. So, your OS will send something to your array to be written, and the card will send a signal back immediately saying it's written even if it's sitting in the cache. You'll want battery backup for this kind of setup.

 

[ddrueding]

Write cache is the big deal, particularly for RAID-5 setups where write performance can suffer. Read cache is done as well (customizable I'm sure), though that wouldn't matter so much with SSDs.

 

[ddrueding]

I should clarify intentions. For example, is it possible to have two SSD drives in RAID 0 and other single drives?

Absolutely. My older, less capable 3Ware card can do that without issue. This card is also supposed to be able to include portions of the same drives in different arrays (eg: first 5GB of 10 1TB drives in RAID-0 for OS/Apps/cache, remaining space in RAID-5 for data security). That is what I would be excited about.

 

[LunarMist]

So the write speed for an average (1GB) file would be equal to the PCIe slot speed, not the SATA interface speed? Of course writes would slow down eventually and reads would be no better than usual.

 

[timwhit]

So the write speed for an average (1GB) file would be equal to the PCIe slot speed, not the SATA interface speed? Of course writes would slow down eventually and reads would be no better than usual.

That depends on the size of your cache. If you have a 1GB cache and nothing else is using it at that time, then yes, theoretically it would be as fast as the PCIe speed.

 

[ddrueding]

And considering that card comes with a 2GB cache, you should be golden.

 

[Stereodude]

An interesting SSD article. link

 

[Stereodude]

Well, I was unable to clone my HTPC install from a PATA HD to a SATA SSD. It just wouldn't boot. In fact it wouldn't do anything. No errors, it just froze. I ended up having to start a clean install on the OCZ Vertex 30GB drive. I will have to finish the setup later. I went back to the spinning PATA drive for now so I could watch something.

 

[ddrueding]

Let me know how that Vertex performs. I have 3 of the 250GB models in my shopping card right now.

 

[timwhit]

An interesting SSD article. link

Geez that was a long article, but I made it through the whole thing. Very interesting. Too bad I still can't afford an Intel X25-M. That one part would cost almost as much as my entire HTPC.

Hopefully, within the next year or two all of these controller manufacturers will have learned how to do what Intel is doing.

 

[LunarMist]

That is interesting, yet nothing is near the X25-E in writes. I wonder if some of the reason for good performance is that it is a 32GB drive with extra, hidden space rather than 40GB (half of the MLC X25-M)?

So where is the 64GB X25-E? I want one now. 32GB is really not enough.

 

[ddrueding]

So where is the 64GB X25-E? I want one now. 32GB is really not enough.

Right here. For about the same price as we paid for the 32GB Funny enough, I just closed Spacemonger after thinking the same thing.

So am I going to buy your 32GB instead and RAID-0? Or the other way around?

 

[Fushigi]

Wow. Thanks for reminding how much buy.com's site sucks.

 

[LunarMist]

It is not just the site. http://www.resellerratings.com/store/Buy

 

[ddrueding]

<shrug> I just ordered something there that I couldn't find anywhere else. It shipped the same day. I'll tell you if it arrives on Monday. Seems they are doing some of that Amazon "other vendors" thing. That is bound to get you crappy ratings and complaints. I only ordered from Buy.com directly.

 

[LunarMist]

You ordered it already? We should not be surprised. I will wait for a while.
I can't do much with computers until my injuries have healed to a reasonable degree.

 

[ddrueding]

No, I ordered something else (2.5" SATA hotswap enclosure)

To prepare for the new SSDs I anticipate getting soon.

Sorry to hear you are injured?

 

[Santilli]

David:
Is that box capable of multiple SATA connections, and, what is the maxium data transfer rate possible?

Doesn't really say in the manual...

 

[ddrueding]

All it does is hold SATA drives (it can do more with SAS, but ignore that). Since all it does is hold the drives, the maximum speed is that of the drives, and whatever you plug them into.

 

[Santilli]

I guess what I was asking is what is the maximum throughput you get out of SATA, one channel? How much is a SATA raid card? Any motherboard chipset limitations?

 

[LunarMist]

Realistically a transfer rate of about 270 MB/sec. can be achieved per drive from buffer to host. SATA 3.0 will be about double that. SATA RAID is limited by the processor and PCIe implementation which is usually 8x for the second slot. Some boards may have more lanes. How much do you want to spend for speed?

 

[ddrueding]

Current Max is 300MB/s per channel. Depending on what RAID mode you want, you can get good RAID performance off the onboard for RAIDs 0, 1 and 10. I wouldn't bother with any of the stuff between that and the Areca/3Ware level. Once you go there, you can saturate an 8x PCI-E connection (2GB/s). If you were looking for the high-end of the bang/buck scale, I would point you towards this:

Areca ARC-1680IX-16-4G w/4GB Cache (16 Port, 8x PCI-E)
16x OCZ Vertex 250GB SSDs
2x Supermicro M28E1

Stuck into a RAID-0*, it gives you 4TB of 2GB/s, 0.2ms latency storage in 4 full-height drive bays for about $15k. The loudest thing will be the fan on the RAID card.

*Redundancy is too expensive to keep in SSDs, get a pair of 2TB drives to store a near-realtime backup if you don't need massive uptime numbers.

 

[Santilli]

I was actually thinking more low rent. My current motherboard has the following slots:
http://www.supermicro.com/products/motherboard/Xeon/E7505/X5DA8.cfm

PCI Expansion • 1x 64-bit 133/100/66MHz PCI-X (3.3V) slot
• 2x 64-bit 100/66MHz PCI-X (3.3V) slots
• 2x 32-bit 33MHz PCI-X (5V) slots

and
Chipset • Intel® E7505 chipset
• MCH + ICH4 + P64H2
SCSI • Adaptec AIC-7902 Controller
• Dual-Channel Ultra320 SCSI

Now, in theory, IIRC, 266 mb/sec should be easy, and 512 possible.

The problem I've had in the past is that when actually pushed, the chipsets come nowhere near the standard for speed. I will admit that the only time that's been a problem with this motherboard is using a Zero insertion card from adaptec uke:

I'm pretty suret the 1 X 133 slot has the Megaraid 3201 LSI card in it, and, that's connected to a 5 drive, SCSI Supermicro box, similar to the one David posted to above.

The onboard scsi is never used, for the simple reason no one makes a Raid 0 card that has a fast enough chipset to get it over 80-90 mb/sec, that costs less then the LSI megaraid card did. Also, 3 10k 146 gig Cheetahs is fine for fast storage, and, for slower, the SATA drives are now pulling near 100mb/sec on the card in one of the 64-bit 100/66MHz PCI-X (3.3V) slots.

All that said, I'm wondering what the actual through put levels would be with this motherboard, and a new generation SATA card?

Also, how well do Solid state drives work in Raid 0? With the Megaraid 3201 Controller, I found 2 drives to be the sweet spot. More drives, seems like a bit of a lag in seek times, with higher sustained through put.
With two drives, I notice a very large increase in sustained transfer rates, and, it seems that random seeks are much faster as well. As I add more drives, I seem to get less increase in actual performance.

The appeal might be just two SSD's, in raid zero. Even with SATA 1.5, and a max transfer rate at 127 mb/sec, one might feel a snappier system due to the near instant seeks?

I'm also wondering if a PCI-X card, in one of the 64 bit slots, might not actually give you nearly 300 mb/sec, with a couple SSDs?

 

[ddrueding]

I mentioned the Supermicro M28E1 here and other places. It looked like a great way to hold a bunch of 2.5" drives in a normal tower chassis. Due to my stupidity, I didn't RTFM until it got here. On page 3-5, at the bottom, it says the following:

NOTE: Ports #4, #5, #6, and #7 are available on the E2 Models only.

So it looks like they sell 2 versions of their 8-in-2, priced within 15%, where half the thing is disabled on one of them.

I know this is my fault, but I'm still ticked off.

 

[LunarMist]

So you are spending $15K to play that video game?

 

[LunarMist]

The appeal might be just two SSD's, in raid zero. Even with SATA 1.5, and a max transfer rate at 127 mb/sec, one might feel a snappier system due to the near instant seeks?

Just get one X25-E on a SATA 2 or SAS 64-bit PCI-X controller. I would not spend too much on one, given the obsolescence of your system. SATA 1 is noticeably slower, but faster than your old SCSI drives of course.

 

[timwhit]

Just get one X25-E on a SATA 2 or SAS 64-bit PCI-X controller. I would not spend too much on one, given the obsolescence of your system. SATA 1 is noticeably slower, but faster than your old SCSI drives of course.

I would go for a X25-M. Larger size and the performance is very similar. Unless, you're running a heavily used database.

 

[Santilli]

David:
While it may not use all the ports on your card, isn't 4 x 3gb throughput enough? The drives should still show up in the card bios, and, be raidable, right, even if they are on 4 channels, instead of 8?

"Just get one X25-E on a SATA 2 or SAS 64-bit PCI-X controller. I would not spend too much on one, given the obsolescence of your system. SATA 1 is noticeably slower, but faster than your old SCSI drives of course. "


?????

Sata-1 real maximum throughput is about 127 mb/sec, isn't it, despite the claimed 150 mb/sec.

My 'obsolete' scsi LSI 320-1 is capable of 320 mb/sec, with a 128 mb on card cache?

Wonder if anyone makes a SCSI SSD?

 

[timwhit]

Wonder if anyone makes a SCSI SSD?

I don't think so, but you can hook up a SATA SSD to a SAS controller.

 

[Santilli]

I wonder if 4 x 15.4 Cheetah 74 gigs, at 93 mb/sec, in raid 0, would be nearly as fast as an SSD?

Each drive is now 65 dollars, which is why I bought SCA: amazing price drops on very fast drives...

 

[ddrueding]

I wonder if 4 x 15.4 Cheetah 74 gigs, at 93 mb/sec, in raid 0, would be nearly as fast as an SSD?

Each drive is now 65 dollars, which is why I bought SCA: amazing price drops on very fast drives...

Not in the way that matters. It is all about latency now for most applications, and nothing with moving parts is even in the race. RAID level doesn't play a factor. Even 5400RPM drives can do 100MB/s.

 

[Santilli]

David, it's a bit ironic, that that was always my point in storagereview.... and, why I loved 15k scsi drives, vs. the 7200 rpm drives they always tried to push...

Still, that said, 4 15k's at 92 mb/sec raided, aren't really going to appear slow...

 

[LunarMist]

92 MB/sec. is nothing. Why are they so slow? Are you running a server of some kind?

 

[Mercutio]

Who cares about 92MB/sec? We don't buy 15krpm drive for STR but for access time.

I'm up to three X25-Ms now. I've got one in my gaming PC and one in a Thinkpad. Not sure what I'm going to do with the third one yet. Maybe RAID0 in the game machine.

Apropos of nothing, I found this post on Hexus.net on how to enable Intel Southbridge RAID after installing Windows.

 

[Santilli]

92 mb/sec isn't all that bad. It's not the 135 mb/sec that the 15.6 gives you, but, they aren't 60 dollars each, either, yet.

Mercutio: What do you think of the X-25M?

My home machine is in a server box, it does run and SCA box with SCSI 320, and a LSI Megaraid controller 320-1. Also the

 

[Mercutio]

It makes my systems faster. It doesn't help me much for gaming, since I primarily play an MMO that depends on on my internet connection for loading. Most of my content is on network servers, so it's not being used for that, either.

Program loads are super-fast unless I'm loading 50 or 60 tabs worth of Firefox (which is not fast ever) and on my Thinkpad I really appreciate it when I'm coming out of hibernate

 

[Santilli]

HMMMM.
I'm getting 100-120 mb/sec, and, the RAT on two raid 0 Cheetah 15k's aren't slow.

That said, ONE Cheetah 15.5-6k will do 135 mb/sec. My guess is two might get around 200 mb/sec. I can take the 147 10k's and put them in a Raid 1 mirror. While not solid state, they don't cost 800 dollars for 256 gig.

 

[ddrueding]

SCSI is cheaper than SSD, but it isn't faster at anything, really.

In my system, I've actually ended up with many tiers of storage.

1. Fastest - A pair of X25-E 32GB in RAID-0. OS, Primary Apps, Small Workspace
2. A pair of X25-M 160GB in RAID-0. Large workspace
3. Four 300GB Velociraptors in RAID-10. Main Storage
4. Biggest - 4 2TB SATA drives in RAID-5. Backup and Long-term storage.

There is no practical way to run fast with a single tier these days. I would keep the SCSI for main storage, but get a 30GB Vortex for $129. Really, it is a whole new world.

 

[Santilli]

David:
I need at least 70 gigs for a boot drive.

I also use removeable sata drives, scsi for storage, and, scsi for boot.
Cost benefit would be good, here...

 

[ddrueding]

If you can't get by with 60, the next size up is 120GB for $349. Just a hair more expensive than a 15k 300GB SAS drive. Crazy, I know, but better.