Intel Smart Response Technology

Is SSD caching really effective at boosting PC performance?

Intel's Smart Response Technology (SRT) was introduced in 2011 to boost the overall performance of computers with an Intel CPU. Intel SRT enables a SATA solid state drive (SSD) to serve as a cache for a hard disk drive (HDD), resulting in faster read/write speeds.

Intel's Smart Response Technology is exclusively available for PCs running Windows 7 and later.

Solid state drive, artwork
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What Is Intel's Smart Response Technology?

Solid state drives offer extremely fast data access and load times, but they typically provide less overall storage and come with a higher price tag than hard disk drives. By combining the two technologies, SRT enables the Intel processor to access data in the fastest, most efficient way possible.

Enterprise-class servers have long used solid state drives as a form of cache between the server and their hard drive arrays to boost performance without the extremely high cost of a full SSD array. Intel introduced this same technology to many of its personal computers several years ago with the Z68 chipset in the form of SRT.

What You Need to Use Intel SRT

Using the Smart Response Technology with the compatible Intel-based computers requires the following:

Before you set up SRT, you should format your solid state drive using the NTFS file system. The BIOS setting for the hard drive controller must also be set to RAID mode rather than ACHI mode. Consult your motherboard documentation for how to access the BIOS to make the change.

How to Set Up Intel Smart Response Technology

When you launch the Rapid Storage Technology program, select the Accelerate tab, then select Enable acceleration.

enable acceleration

It will then ask you how much of the SSD (up to 64GB) you want to use for the cache. Choose your hard drive under Select the disk or volume to accelerate, choose an acceleration mode, then select OK.

Choose how much of the SSD you want to use for the cache, choose your hard drive, choose an acceleration mode, then select OK.

SRT Acceleration Modes: Enhanced vs. Maximized

Under Select an acceleration mode, you can choose between Enhanced or Maximized. This will affect the performance of the cache via how it writes data to the drives:

  • Enhanced mode uses a method called write-through. When data is written to the drive, it is written to both the cache and the hard drive at the same time. This keeps the performance for writes to the slowest writing device, which typically is the hard drive.
  • Maximized mode uses a system called write-back. When data is written to the system, it is written to the faster cache first and then backfilled to the slower hard drive. This gives the fastest write performance possible, but it also has one big drawback: In the event of a power failure or crash, it is possible that data will be corrupted on the hard drive if it has not been fully written. As a result, this mode is not recommended for any form of critical data system.

Intel SRT Performance Test

In order to see how effective Smart Response Technology is, we set up a test system with the following hardware:

  • Motherboard: ASRock Z68 Pro3
  • Processor: Intel Core i5-2500k (default speeds)
  • Memory: 8GB (2x4GB) G.SKILL Ripjaws DDR3 1600MHz
  • Hard Drives: Two WD Caviar SE16 640GB SATA in RAID 0
  • Solid State Drive: OCZ Agility 3 60GB SATA III

The big difference in this setup compared to what many will use is the RAID 0 setup. The Smart Response Technology can work with a single hard drive or a RAID array. RAID arrays are designed for improved performance.

We wanted to see if SRT will give a performance boost to a system that is already using an existing technology to accelerate performance. To test this, we recorded the following CrystalMark benchmark data for just the RAID array:

  Read Speed Write Speed
Sequential 129.5 MB/s 64.8 MB/s
512k 29.32 MB/s 64.84 MB/s
4k .376 MB/s 1.901 MB/s
4k QD32 1.598 MB/s 2.124 MB/s

Next, we ran the same benchmarks across the OCZ Agility 3 60GB SSD to get its performance baseline:

  Read Speed Write Speed
Sequential 171.2 MB/s 75.25 MB/s
512k 163.9 MB/s 75.5 MB/s
4k .24.34 MB/s 57.5 MB/s
4k QD32 48.39 MB/s 72.88 MB/s

Finally, we enabled the caching with the Enhanced mode between the RAID 0 and the SSD, and then ran CrystalMark:

  Read Speed Write Speed
Sequential 158.6 MB/s 74.18 MB/s
512k 155.7 MB/s 62.08 MB/s
4k .22.99 MB/s 1.981 MB/s
4k QD32 78.54 MB/s 2.286 MB/s

These results show that in terms of data writes, the system is slowed down to the slower of the two devices because of the write-through method. This greatly diminishes the sequentially written data as the RAID 0 was faster than the SSD. On the other hand, reading data from the system, which is the primary purpose of the caching, has been improved. It is not as dramatic for the sequential data, but it is a huge improvement when it comes to random data reads.

Intel SRT Performance Test

To take it a step further, we timed a few different tasks on the system over multiple passes to see how the caching improved their performance. We decided to look at four different tasks to see how the cache affected the system.

First, we did a cold boot to the Windows 7 login screen minus the hardware POST time. Second, we tested the Unigine graphics software from launch until the benchmark started. Third, we tested out loading a saved game from Fallout 3 from the load screen to being able to play. Finally, we tested opening 30 photos simultaneously in Photoshop Elements. Below are the results:

  Cold Boot Unigine Fallout 3 Photoshop Elements
No SSD Cache 28 sec 40 sec 13 sec 19 sec
SSD Cache Pass 1 23 sec 35 sec 13 sec 19 sec
SSD Cache Pass 2 18 sec 24 sec 8 sec 19 sec
SSD Cache Pass 3 16 sec 24 sec 7 sec 18 sec
SSD Cache Pass 4 15 sec 24 sec 7 sec 18 sec

The most interesting result from this test was from Photoshop, which saw no benefit when loading multiple graphics into the program with the cache compared to the standard RAID setup. This shows that not all programs will see benefits from the cache. On the other hand, the Windows boot sequence saw a nearly 50 percent reduction in the amount of time it took to get into the system, as did loading a save game from Fallout 3. The Unigine benchmark also saw a 25 percent reduction in loading time from the caching. Thus, programs that have to load a lot of data from the drive will see benefits.

Intel SRT vs. Using a Dedicated SSD: Which is Better?

Intel's Smart Response Technology is most useful for people with existing systems that wish to boost their computer's speed without the hassle of rebuilding their operating system or doing a clone process to move data from a hard drive to an SSD. Instead, they can purchase a small SSD and drop it into an existing Intel system that supports Smart Response Technology. For those building a new system, it is still more beneficial to use a good sized SSD as a primary drive and then a large HDD as a secondary drive.