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IT Bods: Solid State HDDs!


RedM

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I might be in a position to get PC components very cheaply soon. So I've been day-dreaming about an ultimate gaming rig.

 

What is the general opinion of solid state drives? To a layman like me they appear to be faster and quieter. Am I right in thinking that they'll produce less heat too and draw less power?

 

At the price I should be able to get one for I'm looking at a 250gb drive as the only drive. Can I assume Vista and A N Other Linux distro see them as normal drives?

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They're great for laptops where you don't need a lot of space and power consumption is much better with SSD... For a desktop PC I don't know, never used one. Seek time is obviously very fast, but what are these drives like with sustained read/write compared with a Raptor say?

 

If I were building my ideal PC I'd probably just stick 3 disks in a RAID-5 array.

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SSD may be good for your Windows partition and may save you a little boot time, but the main benefits are lower power draw, less noise and less heat as a few here have said. SSD is *not* imho a viable or cost effective solution for desktop machines for a couple of years yet.

 

Check out the 300Gb WD Velociraptor drive here, it's a normal HDD.

 

http://www.reghardware.co.uk/2008/09/08/review_wd_velociraptor_hdd/

 

I'd go with JustGav here, if you want performance get your Raid on. If you got a 2x2 Raid 10 array with say 4x300Gb Raptor high spin speed drives that would absolutely fly. This means though whilst you're buying 1200Gb of storage you're only going to have 600Gb usable (roughly £1.20/Gb). Yes an SSD equivalent of this would absolutely fly and max out a 4Gb fibre channel connection, but that's gonna cost you more than £1000 (roughly £2/Gb), add on the FC card and raid then say £1250. All for 500Gb of storage space. Are you that well off? :) The OCZ kit is nice and crucial are coming down in price. Intel is outrageously expensive for what it is. Even if you did spend £1250 on some storage, you're just moving the bottleneck elsewhere. Computers are the same as cars, there's always going to be something performance inhibiting somewhere in the system/engine. You'd want to next get some low latency RAM or a faster bus mobo, or a CPU with more L1/L2/L3 cache.

 

SSD is not mature enough yet. I work for an investment bank and we're one of IBM and EMC's biggest non-governmental clients in storage (think 150+ petabytes). SSD isn't mature enough for big servers or big performance yet unless you spend absolutely ridiculous amounts, so for now stick with big spinny platters at least until 2010.

 

Heck we've look at SSD, we fine tune some applications so they only use the outer half of the HDD because that works that liiiittle bit faster. 16 x 73Gb drives of the kind we use cost about £10,000 list price. And that's still better value for money than doing it SSD.

 

Hmm. I may need to lay off the caffiene. Feel free to PM me if you want to talk about anything storage related.... as it's my job!

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Hmm - I'd skip the raptors and just go straight for a 15k SAS drive if you're going to stay with platters. Use a couple of 73's for boot and then a couple of 1TB SAS drives for your bulk storage and you have the best of both worlds for less than £1k.

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Hmm - I'd skip the raptors and just go straight for a 15k SAS drive if you're going to stay with platters. Use a couple of 73's for boot and then a couple of 1TB SAS drives for your bulk storage and you have the best of both worlds for less than £1k.

 

Are any consumer level motherboards using SAS now? I know plenty of server oriented ones are.

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I wouldn't bother with onboard RAID for anything. Except maybe using that part of the board for cleaning my shoes.

 

If you're going to use RAID, don't ponce about with onboard RAID - get a proper controller. Depending on your budget, the Adaptec range are good at the moment, and do SAS. The 2-series do R1, 10 and 0, the 3-series adds R5 and the 5-series adds R6 (the 3-series theoretically does R6, but, well, just don't on it, ok).

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I wouldn't bother with onboard RAID for anything. Except maybe using that part of the board for cleaning my shoes.

 

If you're going to use RAID, don't ponce about with onboard RAID - get a proper controller. Depending on your budget, the Adaptec range are good at the moment, and do SAS. The 2-series do R1, 10 and 0, the 3-series adds R5 and the 5-series adds R6 (the 3-series theoretically does R6, but, well, just don't on it, ok).

 

Sure you could spend more money for a SAS card, then pay a lot more for SAS discs.

 

...or you could just realise that your home PC is not a mission critical database server and just stick with onboard RAID and cheap SATA discs.

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Sure - and if that had been the class of solution that RedM had been after that's what I'd have suggested. As he was talking about using SSD's and the like it was clear that he was talking about somewhat higher classes of specification.

 

Mind you, I still wouldn't recommend onboard RAID for anything - for the £150 it costs to get a 2405 you can get a controller that will outperform any onboard solution, can properly handle a failure and gives you SAS capability. We use them with SATA disks here because, as I say, they're no more expensive than a SATA controller of the same specification.

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you can get a controller that will outperform any onboard solution

 

Any benchmark figures to prove that? The onboard solutions are still a dedicated chip after all, if you were talking about software based RAID I'd agree with you completely.

 

I'm sure you could spend a lot of money on a separate card that would do 10 SAS disc RAID5 a little bit faster but in the real world on a home PC is there really any difference?

 

As for Martin's budget, these things aren't in the realms of enterprise cost and use any more. They're cheap and being stuck into all sorts of small cheap computing devices.

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I have plenty of benchmarks of dedicated controllers. I could put some together using onboard if you really want, it'll just take me a few hours. Until I do that, simply taking an otherwise identical system and installing a proper 3Ware controller instead saw significant improvements in pretty much every area of disk performance. Ah, there is a link here: http://dl.maximumpc.com/Archives/MPC0508-web.pdf PDF page 30

 

Onboard controllers are for the main part 'FakeRAID' - google the term for greater explanation, but in essence the motherboard sees the two individual disks and then, in collaboration with the OS driver, presents a single device to the operating system. This method makes use of the system processor and system memory, neither of which is as suited to the job as a dedicated controller.

 

Other problems with FakeRAID are that in a disk failure situation it is usually the case that the system will crash - especially if it's disk 0. A reboot will usually allow the system to restart, but then you get situations where a disk may be failing and causes multiple OS crashes. Another one is that IME FakeRAID controllers often get seen 'through' by Linux - so the operating system sees the actual physical disks instead of whatever logical device is being presented to the OS. Yet another is how in many cases the performance of a mirror pair is negligable improvement over a single disk for reads as well as writes, because the 'controller' isn't interleaving requests, or optimising read/write queues.

 

The best example of how proper controllers can benefit most systems can be seen if you start a disk intensive operation, and then kick off a CPU intensive operation. With FakeRAID either the I/O performance will suffer as the CPU load increases, or the CPU performance will suffer as the CPU struggles with the workload. If you then perform the same test on a system with a dedicated controller the I/O workload if simply offloaded to the controller, allowing the system to get on with other tasks. Another - FakeRAID solutions sometimes use RAID 0+1 instead of RAID 10, which isn't as good.

 

To put it into a gaming context, it means that streaming games will background load the next area usually without you even noticing, whereas onboard solutions will often suffer a drop in framerate for the duration - and, perversely, they'll often suffer a worse framerate drop than if you hadn't used a RAID solution at all!

 

So, for someone looking to build the ultimate gaming rig, which is what RedM said he wanted to do, the best way to get to that 'Ultimate' is a dedicated controller. For anyone else, my recommendation is to either not use RAID (the KISS strategy), or do it properly. Fake RAID solutions are full of caveats which, if not fully understood, can lead to disappointment and potentially data loss.

 

The 2405 I mentioned doesn't support R5, and a 10-disk R5 is a daft idea anyway, but it will almost certainly be faster than Fake RAID in all areas.

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