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【Performance Test】DRAMeXchange 2011 SSD Performance - SSD Controller Chip is Critical to Performance

Published Jun.02 2011,13:56 PM (GMT+8)



SSD Controller Chip is Critical to Performance

SSD contraller ic and nand flash ic are main part of SSD board.

The SSD performance depends on the NAND Flash chip quality, batch number and cost. However, its key factor is the SSD controller chip as it is responsible for the communication between computer and Flash chips used in SSD, the management of data input and output, the control of writing methods and blocks as well as the fault tolerance of data read/write. So to speak, it is the nerve center unit of the SSD.

SSD controller chip is an ARM processor with great programmability. Some SSD controller makers will cooperate with original Flash chipmakers to optimize the firmware. SSD controller chipmakers mainly come from the USA, South Korea and Taiwan. Currently, American Marvell, SandForce and Korean Indilinx are mainstream brands in the market. Taiwan's JMicron also performs well in shipment. During this test, there are also products adopting American Initio and Taiwan's Phison controller chips. Taiwan's SMI SSD controller chips are mainly used in enterprise computers so we did not use them during this SSD performance test which centered around consumer computers and involved small and medium enterprise servers and stations.

With SSD controller chips and MLC NAND Flash chips, the best way to boost performance is to use multi-channel technology and good algorithm. It is normal to supplement with DRAM memory for read/write data cache. Some DRAM memory chips are welded to SSD circuits together with SSD controller chips while others adopts embedded design to be integrated into controller chips for better performance.

According to DRAMeXchange, the SSD controller chip accounts for 10%~25% of the total SSD cost but the Flash chip itself costs most. If SSD controller chips with advanced specification are to be used, it is rather economic to produce large storage based SSDs in light of the high cost.

Besides, as RAID 0, one of RAID technologies can be used to double the data transfer rate of the hard drive, some SSD makers and SSD controller chipmakers work together on dual chip solutions, which is supposed to double the performance of the single controller chip SSD. In the case of single controller chip SATA2 SSD, if it originally has 60 GB capacity and 280 MB/s transfer rate, after changed into RAID0 architecture with dual chip solutions, the SSD is able to reach over 500 MB/s in transfer rate and 120GB in capacity. If it is SATA3, RAID0 can turns out the express SSD at a transfer rate of 720 MB/s.

In the SATA3 field, only Marvell and SanForce have delivered corresponding SSD controller chips so far. The former product is adopted by Crucial under Micron. Intel also uses Marvell products for its own SATA3 SSD product line and plans to put SandForce chips into the next generation SATA3 SSD products in the latter half of 2011. In the competition of SATA3 SSD controller chips, the R&D workforce and the cooperativeness with Flash chipmakers are expected to determine the winner.

Seagate and Samsung Collaborate on SSD Controller, SSD giant OCZ purchased Korean Indilinx in 1Q 2011. SandForce received investment from Seagate. Both facts suggest the great potential of business opportunities in the SSD controller chip market.

The most important thing for SSD controller chipmakers is how to cooperate well with different or specific Flash chipmakers in addition to the algorithm and cache architecture so as to optimize the performance of different or specific brand Flash chips in the SSD.