We recently borrowed a Promise Fastrak TX4650 RAID card for our how to build a NAS box guide, but we were still curious whether the card is faster than an on-board RAID controller. So, with four Hitachi Ultrastars in hand, we fired up the test rig.
The Fastrak TX4650 is powered by Promise's own PDC42819 chip which uses the CPU for its calculations to keep the cost down. It has four SATA 3Gbps ports pointing towards the front of the case and a 1x PCI Express connector. The card has its own BIOS and is bootable, so an OS can be installed to it; Promise includes drivers on its website should they need be injected early in the OS install.
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Unfortunately the PCI-E spec supported is only 1.1, which is limited to 250MB/sec regardless of whether a more modern 2.0 slot (500MB/sec) is used or not. On the plus side though, the four SATA ports support all manner of RAID configurations: 0, 10 (0+1), 5 and JBOD with online RAID migration to 'higher' RAID levels (0 to 5, for example) and RAID expansion (adding extra disks).
The card has pin-outs for either a global activity LED across all four ports, or each individual port if you want to mod something more fancy. The PCB underneath also has solder points for two eSATA ports, but this hardware is not part of the TX4650 card.
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Controller:Promise PDC42819 controller
Connector:1x PCI Express 1.1
Ports:Four SATA 3Gbps
Disk support:Eight logical drives via multiple LUNs
Miscellaneous: Online RAID expansion, online RAID migration, SMART monitoring support
We setup the RAID arrays on each of the controllers in their separate BIOSes using the four Hitachi Ultrastar hard disk. Where possible we enabled write caching and turned off disk spin-down in Windows to avoid inconsistent results. We then ran a range of tests to determine the performance of the drives in both RAID 0 and RAID 5.
2.93GHz Intel Core i7-940 (Intel TurboBoost and power saving states disabled)
6GB Crucial DDR3 1,600MHz CL8 DDR3 memory
Gigabyte GA-X58A-UD7 motherboard (F6 BIOS)
Seagate Barracuda 7200.12 1TB (for OS)
Asus ATI Radeon HD 5870 1GB
ATI Catalyst 10.7 WHQL
Microsoft Windows 7 Home Premium, 64-bit
Promise FastTrak TX4650 Driver 126.96.36.199
Four Hitachi Ultrastar A7K2000 2TB SATA 3Gbps hard disks