Advice on my Raptor/RAID0 configuration

BeelzebubUK · 10 Nov 2006 at 19:33

At the moment I have the following :

2x 150GB Raptors set to RAID0

These are partitioned into a 98GB for Windows + applications and 181GB for games.

The Windows partition is only using about 10GB and the games partition about 30GB currently.

Also have a 250GB SATA drive for storage/backup + page file which is split into 2x 116GB partitions .

Is this the best use of the raptors or would anyone suggest another configuration that would give any performance benefits. I've not had any reason to complain but just wondering if theres anything better I can do ?

NachT · 10 Nov 2006 at 21:12

Thats all good there mate, but why have you got your pagefile on the slower drive?

If I were you i'd stick the pagefile onto the Striped Raptors, on the same partion as windows.

snowdog · 10 Nov 2006 at 22:09

NachT said:
Thats all good there mate, but why have you got your pagefile on the slower drive?

If I were you i'd stick the pagefile onto the Striped Raptors, on the same partion as windows.

I agree, pagefile on raid array 1st partition, waste of speed if not...

Aside that, i'd do this :

raid array :
98 gigs= windows&pagefile&most intensive games&apps ( 1st part of hdd is about 40% faster as last part of the hdd, so games like bf2,etc.. on this partition ).
181 gigs= rest of games, prfferably ones that dont need that much hdd loading...

250 i'd do in just 1 partition for backup and/or data only, pagefile is a waste to keep on that hdd....

p4radox · 10 Nov 2006 at 22:48

snowdog said:
1st part of hdd is about 40% faster as last part of the hdd

Seriously? How does that work?

rpstewart · 10 Nov 2006 at 23:35

p4radox said:
Seriously? How does that work?

The disk spins at a constant speed (constant angular velocity) so towards the outside of the disk the linear velocity of the surface is higher than at the centre. This means that there is more data passing under the disk head per revolution of the platter at the outside of the disk, hence data can be read or written more quickly at the outside of the disk than it can at the inside.

BeelzebubUK · 11 Nov 2006 at 00:53

OK - have set the pagefile on C: and I'm copying everything on the 250GB drive to an external ready for scrubbing back to a single 250GB partition.

Is it worth making the Windows partition smaller to take more advantage of the start of the disk or is it not really worth it ?

gadget^ · 13 Nov 2006 at 12:58

sorry for the stupid question whats a page file ?

rpstewart · 13 Nov 2006 at 13:37

It's the virtual memory swap file. It's used by windows to extend the amount of memory available to applications beyond that provided by physical RAM. Contents of RAM used by background tasks are written to the page file after a wee while to allow the RAM to be freed up and used by foreground applications. The effect of this can be seen when you jump between applications on a busy system, it can take a while for something to come to the foreground because the system has to ge the necessary bits back from disk into system RAM.

p4radox · 13 Nov 2006 at 22:30

rpstewart said:
The disk spins at a constant speed (constant angular velocity) so towards the outside of the disk the linear velocity of the surface is higher than at the centre. This means that there is more data passing under the disk head per revolution of the platter at the outside of the disk, hence data can be read or written more quickly at the outside of the disk than it can at the inside.

Cool, makes sense. So the disk is written from the outside edge towards the inside?

Mud · 13 Nov 2006 at 23:07

rpstewart said:
The disk spins at a constant speed (constant angular velocity) so towards the outside of the disk the linear velocity of the surface is higher than at the centre. This means that there is more data passing under the disk head per revolution of the platter at the outside of the disk, hence data can be read or written more quickly at the outside of the disk than it can at the inside.

HDD data isn't stored like CD data? i.e. not constant data/arc angle, so data is not more spread out at the outside? Not saying you're wrong, but that sounds like a right pain from an engineering perspective. More efficient though, obviously.

rpstewart · 14 Nov 2006 at 00:12

It's not identical to CD storage but similar. A CD stores data at a constant size per bit so a piece of data takes up the same space whether it's at the inside or outside of the disk. An audio CD is read using Constant Linear Velocity (CLV) to give a steady bit rate, this is why a CD rotates slower as you get towards the outside.

Originally HDDs stored data in the same way as floppy disks - the disk is broken up into concentric rings or tracks with each track being divided into pie shaped sections or sectors. Each sector stored a fixed amount of data and hence reading at a Constant Angular Velocity (CAV) gave a fixed bit rate which could easily be sync'd with bus clocks etc.

Now that's a nice idea until you realise that the outside sectors are physically much larger than the inner ones but store the same data, this is very inefficient. To get round this modern HDDs use a concept known as Zoned Bit Recording whereby the outer tracks have more sectors than the inner ones. This means that for every revolution of the disk more sectors and hence more data pass under the head at the outside of the disk than the inside.

As you say, it's a pain from an engineering perspective but it's one of the advances which has allowed us to have the large capacities and high speeds we currently have.

Mud · 14 Nov 2006 at 00:16

Very enlightening thanks, electronic engineering isn't my primary field.