Intel Z68 – Smart Response Technology First Impressions

I recently bought a Z68 motherboard with an SSD for trying out the new caching system (Smart Response Technology) that Intel have included. I strongly believe in using an SSD as a large buffer / cache for several reasons:

SSDs aren’t reliable

The problem with SSDs has been their unreliability – the controllers are unreliable with several data loss issues and numerous recalls. The underlying technology also has a finite number of read/write cycles, something traditional HDDs don’t suffer from.

SSDs cost a fortune

SSDs still have a hefty price premium over a traditional mechanical disk. We’re around £1 / GB, which is somewhere around 17x more expensive per GB than my 2TB mechanical drive. Of course the performance makes up for the price – but if you need a lot of space then it’s going to get expensive fast.

SSDs don’t come in high capacities

This is an extension of the high-cost issue mentioned above. OCZ are going to release a 1TB SSD for about $1000, but that's still rather pricey. If the drive would last the long-haul I could probably just about justify it. But if it only lasts 2yrs, then it's just not worth it. Plus with Steam 1TB won't last that long unless I start uninstalling games and/or transferring them to a mechanical drive.

Using an SSD as a boot drive only is awkward

A lot of people get an SSD as a Windows boot drive, and then install only performance-critical apps to this drive. A traditional HDD handles the rest. The problem with this approach is it’s labour-intensive and requires you to jump through quite a few hoops with Steam should you want your game to run off the SSD. I don’t even consider this philosophy an option – a computer should make life easier not harder.

So, SSDs are very fast yet flawed. If you could guarantee reliability it may well be worth investing in 1TB of SSD space to gain the astronomical performance boost. You could overclock your 8-core CPU to 10Ghz and still not get the kind of responsiveness an SSD would give on a 2Ghz dualcore. But I don’t know about you, I’m not spending $1,000 every year or so just because the drive isn’t reliable. Not to mention that SSDs can’t be recovered in the same way a mechanical drive can when it starts to break.

So, this leads me on to caching. The idea is you have a mechanical drive for storing all of your data, and an SSD as a high-speed cache for all of your frequently accessed files. The best of both worlds, the drawback of neither. Now I’m not going to talk about raw performance, you can check Anandtech for that. What I am going to do is give some very, very early first-impressions of caching as offered by Intel.

I’ve paired a Crucial m4 64GB SSD with an Hitachi 2TB 7,200rpm Deskstar 7k3000. I store a LOT of Steam games, as well as all my dev tools, files, etc. Given the manner I use my PC, having an SSD boot drive would result in more time spent transferring files than time-savings from the SSD speed.
Setting up SRT is easy enough – you set the SATA controller to RAID mode in the BIOS, install the perquisite drivers and enable acceleration. I found the UI utility would crash if the driver hadn’t quite loaded. It also seems to interfere with the graphics card, enabling / disabling SRT crashes my AMD driver with 100% consistency.

Now on to the performance. Windows boot up is appreciably faster – not native SSD fast, but faster nonetheless. The big difference is post-boot after you’ve logged in. I’m sure everyone is used to the HDD thrashing away, and Firefox showing up 10mins after login. With caching enabled I can use the system straight away – Firefox is up almost instantly. I also found Zune loads near-instantly too, where before the disk would thrash and all other operations would be interrupted constantly.

Applications on initial load all take the same time as before (but not longer, so there doesn’t seem to be an overhead when caching new data), but on subsequent loads they’re much faster. I was expecting more performance in games if I’m honest, but it’s still a nice improvement. Normal Windows apps gain the most from the caching, and it’s very noticeable.

So my biggest pet peeve with Windows is resolved – the hideous boot time (I of course include the lag after you've logged in which MS seem happy to ignore). The other pet peeve is not, however. When accessing the HDD, if anything needs to access IO it will completely halt. There seems to be a somewhat serial nature to the data fetch which means if the HDD is thrashing – even cached data will take a while. So for example if the HDD has to server 10 file requests, it’ll go through them all before file 11 (on the SSD) is retrieved.  In essence, if the HDD is thrashing, the SSD cache will not help. On the plus side this is less likely to happen in the first place, but it is annoying when it happens. Tasks you often do are performed with haste, but if you throw in a single non-regular task your system grinds to a halt just like all non-SSD systems.

Ultimately I’m pleased with the SSD caching system Intel have. I would really like them to invest heavily in the software. I’m not sure if this is possible with the Windows IO subsystem (which is atrocious, seems stuck in the ‘80s) – but if the driver could pick large queues of data and serve SSD cache blocks as a priority that would be grand. I haven’t used the caching enough to know this, but I also hope the cache strategy is similar to the generational strategy used by the .NET runtime. In short, I hope it’s not just a stack where the last used data is cached, and old data is just discarded to make space. While that seems logical, it means if you installed a 20GB app, it would clear out 20GB of cached data. The new app may only be used once or twice a month, but the cleared data may be accessed every day.

Would I recommend it? Well I was considering spending £80 on an i7-2600k rather than the i5-2500. That £80 covered the SSD, and it’s provided substantially better performance than the minor boost the faster CPU would have provided. So if you’ve got the cash ‘spare’ I would say it’s well worth it. Let’s face it, HDDs have terrible performance and drag the whole system down. Anything that can alleviate that has got to be worthwhile.