Answers to Questions About mSATA Speed
Flash storage that uses the SATA interface is popular in a range of different devices and applications. It has virtually replaced IDE/PATA interfaces that once ruled the market. For applications and devices that want to use the SATA interface but need a small form factor, mSATA is the solution. As with any kind of flash memory, speed is likely to be a top concern on the minds of engineers when selecting mSATA for storage. Here are the answers to some common questions about mSATA speed to help you determine if this is the right flash storage for your design.
Why do some mSATA cards use a DRAM cache and others don’t?
DRAM is sometimes used to up the speed on mSATA SSDs. DRAM cache has a large capacity, so it delivers increased speeds when used in an mSATA SSD, particularly during writing. Similarly, DRAM performs at a higher level than NAND flash, so DRAM can quickly save data that is then written to the mSATA NAND flash to finish the process.
However, DRAM is volatile, so it needs power. If a power outage occurs when data is still in the DRAM cache, then that data may be lost. For this reason, DRAM caches typically aren’t used with industrial mSATAs. Industrial mSATA needs the highest possible degree of reliability and data protection, and the burst of speed provided by DRAM is not usually worth the risk of lost data.
How do the number of NAND components affect mSATA speed?
The more NAND devices that are contained in flash storage, the faster it will perform. When multiple NAND components are present, striping is used to perform reading and writing at the same time on all of the available NANDs. The speed increases with each additional NAND.
Because mSATA devices are limited in physical size, they can only hold a maximum of four NANDs. For comparison, a full size SATA memory device may contain as many as 10 NANDs. The physical size of mSATA does somewhat restrain its speed, but most devices that require a form factor will face the same problem with other interfaces.
Is SLC NAND flash faster in mSATA than MLC?
As a rule, SLC flash is faster than MLC, regardless of the flash design. mSATA industrial SLC flash memory writes a single bit of data per cell. This allows both faster reading and writing than MLC designs, which must read and write two bits per cell. Large block sequential speeds and random write speeds are more affected by the difference in SLC and MLC processing than small block writes.
Let Delkin’s product team help you decide if flash based mSATA is right for your small form factor storage needs. We’re here to answer your questions and assist with product samples today.