WD - 8mb VS 2mb...and where does RAID come in?

[gas-man]

Hello all,

My mobo supports only ATA100, but I have an ATA133 IDE Controller card. That said, I was thinking of getting some more HD space....

Is an 8mb cache really worth the extra money? What benefits would one notice? Also, how does RAID come in to play? What effects (or what is it for that matter) does it have on performance?

The drive would probably be used for big files (ISOs, DVDs, etc.)

Thank you

 

[ronin1967]

RAID has several features depending on how you setup the array(a group of HDD's)

RAID 0- Data Stripping, 2 or more HDD's, Highest performance, no data protection(basically your drives appear as one large drive, but you gain the benefit of faster reads/writes, on the downside if one drive in the array fails the whole array crashes and everything is lost.

RAID 1- Disk Mirroring, 2 or more HDD's, no performance gain, but it creates an identical image of the first drive on the second drive, if the first fails the second takes over. The downside is you have two drives but only use the space of one.

RAID 0+1, 4 or more HDD's, best performance, data security, but again you only gain 1/2 the total real space

Gamers usually use RAID 0, read/writes are almost twice as fast as normal drives...

 

[gas-man]

Very informative, thank you.

So is RAID something that would be supported (included) with a mother board or controller card?

I don't believe my K7D has it

 

[ronin1967]

the motherboard in my sig has a built in RAID controller, if your motherboard doesn't there are several PCI controller cards that would work great(sometime better than built-in controllers)

I have another machine uses RAID, it has a Promise FastTrak100TX2 PCI controller card, there are others, shop around see what you like***make sure whatever you choose has RAID and the type of RAID you want(0,1, 0+1)***

 

[gas-man]

Alright,

Let's say I wanted to stay away from RAID, just to save the controller card cash, is an 8mb cache worth the extra $30.00 or so?

What would be better:

Maxtor 80gb 7200RPM 2MB cache ATA133
WD 80gb 7200RPM 8MB cache ATA100

 

[ronin1967]

to be honest I have ATA/100 HDD's, ATA/133 HDD's some with low cache some with high cache, I have never been able to notice a difference, even benchmarks don't notice big changes, however I can honestly say that RAID 0 makes very noticable changes, and when it's time to benchmark and your dirve is off the chart and performs at 200%

 

[Kartman]

Gamers usually use RAID 0, read/writes are almost twice as fast as normal drives...

Urban Legend.

In order for stripping to be of any considerable benefit, one needs to be doing a lot of reading and or writing of large files. Several entities, including TechTV, has run performance tests based on file sizes for striping RAID and when the files get small (<1MB) the benefit is practically invisible.

Imagine, I would connect 8 drives into a RAID 0 condition and then try to write several 50KB files to that array. Can you imagine with today's hard drives (espeicially the spec. ed. wdc) the ability to cache a 50kb file will completely overshadow any attempt at benefitting from a RAID 0 conditon.

Now, take a 50MB file and yes, you will see a large benefit from RAID 0. Its much easier to bust apart a 50MB file into 6.25MB files and write them onto a 8MB cache drive, but the silliness of benefitting across the board for file sizes is mythical at best.

Of course, one is always open to perform their own tests and get a couple of identical drives, use on-board or add-on RAID and start testing for, say, 50, 250, 500KB, 1MB, 5MB, etc. and see what you get.