Intel Smart Response Technology Explained
By Henry Butt on May 26, 2011
Intel Smart Response Technology (SRT) is designed to bridge the middle ground between traditional mechanical hard drives and solid state drives by combining the two. Although high capacity SSDs are quite expensive, low capacity units are much less expensive and achieve similar levels of performance. Intel’s SRT lets you use a low capacity SSD to boost the performance of a mechanical drive by using the SSD as a cache.
Until now, there hasn’t really been any middle ground between the two. Sure there are products out there like the Seagate Momentus XT hybrid hard drive which boosts read speeds using a 4 GB read cache but, in most benchmarks, these can be easily beaten by Western Digital’s VelociRaptor hard drives.
SSD Caching isn’t actually anything new and has been around for a few years in various different forms like Intel Turbo Memory Technology (a.k.a. Robson Technology), which was launched in 2006. But it hasn’t gained much traction until now with the launch of Intel’s Z68 chipset, which supports I/O caching in the form of SRT.
Smart Response Technology improves performance by storing the files or parts of the files that you access most frequently on the SSD for quicker access. The SRT software is only able to cache some files because there is a limited amount of space on the SSD, so it identifies which are the most beneficial files to cache by monitoring which programs and files you use most frequently. It is also able to identify files that you’re only likely to use once or twice, like audio and video files.
As a result of the software having to learn your behavior, the performance benefits of SRT aren’t going to be noticeable straight away. But the software is able to adapt to your habits over time, which should bring long term performance benefits. Your system will also only display one drive letter despite there being two physical drives in your system.
To use SRT, there are only three items you need. These are a motherboard based on the Z68 chipset, an SSD and a hard drive. The SSD and hard drive can be any capacity, but it’s worth bearing in mind that SRT can only use up to 64 GB of space on the SSD, so it isn’t worth buying a larger one.
Intel sent us their new 311 Series 20 GB solid state drive, codename Larson Creek, which has been designed specifically to be used with SRT. It differs from most SSDs on the market today because it uses SLC memory chips which generally last much longer than the MLC chips used in most SSDs. This does inflate the cost of the drive considerably, though, as SLC chips cost about twice as much as MLC ones.
The drive itself adopts the standard 2.5” form factor, meaning it should fit into most modern PC cases. If not, there are numerous 2.5” to 3.5” adapters available on the market which will only set you back a few dollars. Intel has chosen to use an aluminum enclosure that should protect the insides of the drive well. To remove the enclosure, we must remove the four screws in each corner of the drive.
The drive features the same Intel PC29AS21BA0 controller as a number of other SSDs in their range alongside an ISSI 32MB IS42S16160D-7TLI cache chip. This supports maximum read and write speeds of 200 MB/s and 105 MB/s, respectively. There are only five SLC memory chips in total, which are also made by Intel. They carry the part number 29F32G08CAND2.
In most cases, it’s not going to be possible to use Smart Response Technology without re-installing Windows on your PC, because you must activate RAID mode in the BIOS to enable SRT. We expect that most motherboards based on the Z68 chipset will be set to IDE or AHCI mode by default, like our Gigabyte Z68X-UD5-B3, so you must make sure you change this before installing Windows.
When installing Windows, you must make sure you install it on the hard drive, rather than the SSD which must be left blank. After installing Windows, we must install all the drivers from the CD included with your motherboard. On our Gigabyte Z68X-UD5-B3 motherboard, we had to update the BIOS to the latest F6 version to get SRT to work. We also had to update the Intel Rapid Storage Technology software to the latest 10.5.0.1027 version. Without these updates, the system would not boot after enabling SRT.
After restarting your computer, we can open up Intel’s Rapid Storage Technology software to set up SRT. Along the top menu bar, we must click on the button labeled “Accelerate” which brings up another window that lets us select the SSD for caching and the disk or RAID volume that we want to accelerate. We are also able to select between two acceleration modes, enhanced or maximized.
The two different modes set up the SSD caching in different ways. Enhanced mode is designed for maximum security, reducing the possibility of data loss but also limiting write speed as it writes data to the SSD and HDD at the same time. Maximized mode is designed for optimum performance, writing data to the SSD and only periodically transferring it to the hard drive. This means that if anything should go wrong with the SSD, you could lose some data. The outcome of an SSD failure would depend largely on what the SSD was caching at the time of failure, so it’s difficult to predict how it would affect your system.
During our testing procedures, we used the configuration listed below. The only variable component between each benchmarking session was the drive being tested.
As you will have gathered from the last page, we measured the performance Smart Response Technology using three different programs: CrystalDiskMark, PCMark Vantage, and PCMark 7. We will be looking at the test results from each program in the order they appear in the list above.
It’s important to note that we connected all the drives to SATA-600 ports on our motherboard rather than SATA-300 ports which could cause performance limitations.
We’ve included results for the Kingston SSDNow V+100 SSD for all the benchmarks we ran to give you an idea of how SRT compares to having an SSD as a main drive.
We used CrystalDiskMark’s default configuration for our tests, which benchmarked each SSD using a file size of 1000 MB with five test runs. Please read on to see the results.
In the sequential read test, enabling Smart Response Technology in maximized mode yielded an impressive 38.1% performance gain over the hard drive on its own. In Enhanced mode, there was an even greater 59.5% performance gain over the hard drive alone. In both sequential write tests, there was a 7.4% performance drop using SRT compared to the hard drive alone in maximized mode and a 10% drop in performance.
This could be for a number of reasons. The results displayed were recorded on the third run of the test to give the system a chance to “learn” our behavior. After even more repeats of the benchmark, the performance should be better, as the system will cache more of the data. But the Intel 311 Series SSD has a maximum write speed of 105 MB/s, which is probably the limiting factor in this case. As the hard drive has a higher maximum write speed, the caching of data actually has a negative impact on performance in this test.
In the random read test using 512 KB blocks, there was a much bigger difference in performance than in the sequential test. In maximized mode, there was a massive 249% improvement in performance, and in enhanced mode there was an even greater 272% improvement. In the random write test using 512 KB blocks, there wasn’t any improvement in performance with SRT enabled in enhanced mode. But in maximized mode, there was an 84% improvement in performance.
With SRT enabled in maximized mode, there was a massive 4434% improvement in performance over the hard drive alone in the random read test and a 3714% improvement in the write test using 4 KB blocks. In maximized, mode, SRT also outperformed the Kingston V+100 128 GB SSD by 13% in the read test and by 50% in the write test using 4 KB blocks.
When SRT was enabled in enhanced mode, however, there was no improvement over the standard hard drive in the write test using 4 KB blocks. There was still an impressive 4586% improvement in performance in the read test using 4 KB blocks, though.
We decided to use both PCMark Vantage and PCMark 7 to test the performance of Smart Response Technology, as they give us a good indication of real world performance. Please read on to see the results.
In the Windows Startup test, we saw a huge 468% improvement in performance in maximized mode and 472% in enhanced mode. In the gaming and application loading tests, we saw performance increases of 592% and 1383% in maximized mode and 564% and 1378% in enhanced mode. There were also impressive performance increases in the adding music test of 501% in maximized mode and 481% in enhanced mode.
In the starting applications test, there were massive improvements in both enhanced and maximized modes of 951% and 981%, respectively. In the adding music test, the performance improvements with SRT were much smaller with a 7% improvement in maximized mode and a 3.1% improvement in enhanced mode.
Moving on to the gaming test, there was a 199% improvement in maximized mode and a 194% improvement in enhanced mode compared to the hard drive alone. We also saw reasonable performance gains in the Windows Defender test where performance was boosted by 190% in maximized mode and 185% in enhanced mode.
In our tests, we saw some pretty impressive performance gains with Smart Response Technology enabled compared to using the hard drive on its own. In some tests, it was actually better than the Kingston SSDNow V+100 SSD.
There were a few instances in which SRT had a negative impact on performance but this is because SRT only caches the most used data. This means benchmarks that measure performance by reading all sectors of the drive will not benefit from SRT like the sequential write test in CrystalDiskMark.
One of the main issues with SRT is that the performance improvements are not consistent and aren’t anywhere near as great for applications and processes that you don’t use very often. If you use a SSD on its own in your system, the performance improvements will be noticeable all around, not just in your most frequently used applications and processes.
The Intel 311 SSD 20 GB SSD costs about USD 100, making it a significantly cheaper option than using an SSD like the Kingston SSDNow V+100 128 GB we used for comparison, which costs in excess of USD 250. Sure you will need to add on the cost of the hard drive to use SRT, but most people who have a SSD as their main drive will use a mechanical hard drive for storage too. So for users who can’t afford a SSD as their main system drive but want SSD-like performance, Smart Response Technology with the Intel Larson Creek 311 is a great option.