Explaination on drivers and controlls for HDD and SSD

[aleksanderness]

Hi i never quit gotten the whole driver controll thing with harddrives and SSD's.
As i understod so far, is that you might not get full speed with an SSD disk if it has lousy drivers/controllers ? And with a raid0 (stripe) The driver/controller would be the bottleneck, and limit the speed you would get.

 

[WyomingKnott]

What have you read so far? Have you checked something simple, like Wikipedia?

The main controller issue with SSDs is that the controller (hardware on the motherboard) should be configured (by setting options in the BIOS) to AHCI mode. By default, these are set to IDE mode, which limits the commands that can be sent to the drive and is there for compatibility with older drives and OSes. AHCI mode enables newer features of the drive, be it HDD or SSD.

Two key features that are enabled are Native Command Queueing, which is relevant to both HDDs and SSDs, and the TRIM command. If you have the controllers in AHCI mode, and are running Win7, the OS can pass the TRIM command to the SSD when files are deleted. Otherwise, the SSD will continue to think that that space is in use. As the SSD loses track of available usable space, it slows down in write performance.

Some people believe that the SSD's built in Garbage Collection will deal with this, some do not.

So. The point of all that was that AHCI mode enables features of HDDs and SSDs that are not available in the default IDE mode.

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Drivers are software in your OS. These should not be much of an issue, since you should get the most recent ones every time you do an update. With an Intel-based motherboard, you should install the Intel RST drivers during your system build.

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RAID0 is a different issue. The driver/controller is not a bottleneck for RAID any more than it is for two single drives. The potential issues are having an SATA II controller, which is slower than most SSDs, and having a seperate controller card. Some separate controller cards have only one PCI-E lane, which makes their connection to your motherboard slower than a single SATA III connection. Unless you have an add-in controller card, this will not be an issue.

Finally, putting SSDs in RAID disables the TRIM command, leading to eventual gunking up of your SSDs.

 

[aleksanderness]

Thx a lot

So raid with ssd's is a waist so to speak, as the ssd's will be kinda one time write disks. Wow thats a major downfall, id expect a problem like this to be fixed fast?
If i understod correctly.

 

[JackNaylorPE]

RAID 0 with anything is a waste ..... except for very specific applications such as rendering, video editing, huge databases and the like.

 

[smorizio]

with pc you have to understand read up about bus speed and i/o clocks. alos read about sata and ide specifcation online it free.as of right now there working on sata that can go 12g on pci bus. chipsets are the control chips for the mb once the bios posts. old pc chipset were ide at. then came the ata33 speed and ata66 on a ide cable. sata or serial data storage came out do to the fact that storage vendors and servers had hit the speed wall with scsi and ide. fiber channel was still in the r and d..
ssd in pc now is jut the next step in going away from slow mec drives. the issues now with ssd in a pc..i have one now in my new build is cost and life of the drive. (ssd do wear out there are only so many read/writes with them.) the plus side is with windows 8 and my z77 saberthooth mb i can boot into windows in about 20s. app and web pages open up is a flash. the down side is the swap file and restore partion have to be turned off and moved to a data drive. on my ssd is just word and my main games...anything that i dont need every daya like quicktime is installed on the slower ssd. the other thing that goes with a fast system is ram...running 8 right now..a lot of people are running there system now with 16g...the more ram you have the larger ram disk you can make for the os. ie both the ssd and data drive dont have to keep reading and writing data.

 

[WyomingKnott]

Two clarifications: First, SSDs are not write-once. They do wear out, but after thousands of write cycles. I think that the thing that this refers to is the lack of TRIM in RAID. That doesn't mean that the disk is write-once, because the OS can always write a file to block 456 after it deletes whatever is at block 456. The space gets re-used eventually. But SSDs do massive optimizations and other manipulations of writes, and write faster if they know where all the free space is.

(regulars: Yes, I know that that is a lousy explanation. I'm not going to go into any more detail here).

RAID is not so much a waste as each RAID level is an excellent solution to a specific problem. If you don't have one of those problems, then the only reasons to do RAID are benchmark bragging rights or the pure fun of seeing how different configurations behave. Heck, I used to own a datacenter RAID array just to play with, until SSDs got so fast that a single SSD was faster than my whole RAID box.