Faulty Marvell Chips Delay SATA 6G Launch 90
Vigile writes "The SATA 6G standard offers more than simply a faster 6.0 Gb/s data throughput speed, to wit: improved NCQ support, better power management, and a new connector to support 1.8-inch drives. While modern-day, spindle-based hard drives struggle to keep up with SATA 3G speeds, modern SSDs are nearly saturating the existing standard, and a move to SATA 6G was welcome in the hardware community. It looks like that technology will be delayed, though. The only chip supporting the standard today, the Marvell 88SE9123, is having major issues. Motherboard vendors including ASUS and Gigabyte, which had planned on releasing SATA 6G technology using the chip on Intel Lynnfield platform motherboards later this summer, are having to remove the Marvell 88SE9123 and redesign their boards at the last minute due to significant speed and reliability issues."
Interface speed only (Score:1, Informative)
This is silly. Current hard drives can't even max out the speed of SATA-2. There's no need for faster interfaces just yet.
Re:Interface speed only (Score:4, Informative)
... "modern SSDs are nearly saturating the existing standard" ...
Re:Maybe they should stick... (Score:5, Informative)
Um, Billy Batson would have you know it was Tesla and Edison, not Einstein, arguing over type of current.
Nice try.
Re:Interface speed only (Score:5, Informative)
Intel's X25-M [tomshardware.com] seems to perform 200 MB/s constant throughput. Granted that's "only" 2/3rds of the 3 Gbps that SATA 2 delievers, but the quote was "nearly saturate".
And if we're already at 2/3rds, that's a fairly compelling argument to upgrading. On laptops it can become an issue much quicker, as you usually only have 1 eSATA port, and port multipliers do not increase bandwidth. Hooking two X25-Ms onto a single eSATA 2 port can saturate it while doing non-random transfers easily but still have room left over on eSATA 3.
But if we're merely talking SSD in general, we can always point to Fusion-io ioDrive [tomshardware.com] which bottoms out at 429 MB/s.
Re:Interface speed only (Score:3, Informative)
The Fusion-io ioDrive Duo [tomshardware.com] could, but connected directly into a PCI-E slot rather than SATA, but it is definitely possible to make a drive that will.
Re:Interface speed only (Score:2, Informative)
Can't boot from them, but there you go.
Re:Interface speed only (Score:5, Informative)
Most sequential throughput benches hit the drive with sequential requests, and are not multithreaded. You end up seeing throughput lower than the theoretical interface bandwidth because of the latency involved for each request. A queue depth of 2 or 4 will give an X25 enough heads up to truly saturate the bus. I've recorded as high as 285 MB/sec from an X25-M using an NCQ-capable benchmarking tool.
Also, don't forget SATA uses 8/10b encoding, so you have to account for that overhead as well when calculating theoretical maximum throughput. Doing the math, you'll find 285 comes to 95% of a 3 GB/sec SATA interface. That's way higher than 200 MB/sec and close enough to call saturated.
Allyn Malventano
Storage Editor, PC Perspective