Does partitioning a RAID array reduct the performance gains of RAID?
I’m planning to use three 10,000 rpm Western Digital Rapters in RAID 5 for my dream PC that I’m getting ready to build. I want the quickest possible boot and load times from my hard drives but I also want some protection against data loss (bad experience with RAID 0). I also want to have tri-boot system (Linux, XP and eventually Vista) and am concerned that three partitions would reduce or eliminate the performance gains from my RAID array. Is this true? Any suggestions and advice would be much appreciated. (Storage and back up is provided by a 2Terabyte NAS so I don’t need a huge amount of local strorage)
Tagged with: bad experience • boot system • dream pc • hard drives • Linux • partitions • performance gains • raid 0 • raid 5 • raid array • rapters • rpm • storage • strorage • western digital
Filed under: rpm
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Well separate partitions are not a performance issue if the raid is already striped, go for it.
Partitions will not cause performance degradation on a RAID 5 setup.
Raid-5 is one of the cheapest way to get data protection, at the expense of performance. If you use Raid 5 for your ‘dream machine’ and you plan to use your dream machine for games, you may ruin your dream.
Not only is Raid-5 slower than the single drive (because it has to generate the error-correction code for each write), it can be murder when you do lose a drive, or you get enough bad sectors that the firmware ask you to replace the bad drive. The firmware has to build the data (same effort as error-code generation) for the replaced drive from the two remaining original drives, one small block at a time. You basically lose the use of your PC until that rebuild is completed (probably an overnight event).
What kind of fans come with your tower to allow you to install three 10000 rpm drives. WD Raptors are meant for industrial servers. According to their specs, each of these drive dissipates 10 watt each (that’s heat) when doing read/writes. Three of those drives would generate about 30 watts of heat. Industrial server often have redundant fans. Otherwise, a fan failure can cause all these drives to self-destruct pronto. Also, big fans are noisy. Can ruin your gaming experience.
If you are planning a gaming super system, I’ll recommend using a Raid-1. A Raid-1 will run faster than the single drive, and quite a bit faster than Raid-5. Reading from a Raid-1 is faster than a single drive. WIth writes (which you wouldn’t be doing much in gaming), your Raid-1 will do a write to each of the two drives for every write performed by the software, but the 2nd write are done only when the drives are free, which helps with Read speed. In addition, when you replace a bad drive in a Raid-1, rebuilding is nothing more than copying what’s on the original good drive to the replacement drive. No error-correcting code is generated. It will be much faster.
The 3-drive Raid 5 allows you to use 66% of the disk space you buy; the 2 drive of a Raid-1 lets you use only 50% of the disk space you buy. In general, two bigger drives is cheaper than three smaller drives. You can do the math to determine the MB/$, but if you really want a high performance gaming machine, use the Raid-1.