There are several key factors to consider
when comparing the specs of HDDs:
(1) rotation speed in rpm, which directly affects
time to do one-half rotation aka average rotational
latency e.g. 5400, 7200, 10000 and 15000 rpm;
(2) time to move the READ/WRITE heads from
track-to-track and from outermost to innermost tracks;
for larger diameter platters the latter "access times"
can be very large;
(3) recording density: either horizontal or
perpendicular magnetic recording ("PMR");
(4) size of the internal cache e.g. 2MB, 8MB, 16Mb and 32MB;
(5) speed of the interface e.g. 133MB/sec, 150MB/sec, 300MB/sec,
400Mb/sec (fibre channel) and the upcoming SATA/6G = 600MB/sec;
(6) the esoteric features like Native Command Queuing (NCQ),
SAS (Serial Attached SCSI), staggered spin-up, time-limited
error recovery, vibration tolerance for RAID setups, etc.
WD's Raptors do not use PMR, and for that reason
WD's models that do use PMR are now about equal
in raw transfer speeds to the Raptor's raw transfer speeds:
"raw transfer speed" here means the rate at which
data bits pass under the READ/WRITE heads.
There is a premium to pay for 10,000 rpm drives;
you may find that the newest 7,200 rpm HDDs with PMR --
like WD's RE2 and RE3 models -- perform quite well
when hosting the OS:
But, for consistent performance overall,
WD's latest VelociRaptors are still very competitive
for hosting the OS, their 10,000 rpm rotation
speed necessarily reduces rotational latency,
and their small platter diameter means that
outer-to-inner head movements are minimal:
WOW, many thx to you MFRS, your explanation is more than enough for me
Just one more simple question :
- IF i use an OLD (average performace) HDD to be my main hdd (booting O/S), and then let's say the NEW (high performance) HDD to store application, games, etc.... Will my old hdd going to bottleneck the good hdd? (since the old one is accessing my O/S). Or should i use the old one as application / games hdd?
In general, it's better to host your OS on the faster HDD
because the C: partition is accessed so often e.g
during program launch, paging activity, and such.
If you are really interested in boosting performance
without spending lots of money on a super fast
storage subsystem, consider installing a ramdisk
using the excellent software from www.superspeed.com :
We've moved our browser caches to a ramdisk
using this software, and our results have been
excellent all around: IE7, Firefox and Opera
all permit re-locating the browser cache,
Chrome does not (yet: we suggested it to Google).
We are measuring 3GB/second during "raw reads" (3,000 MB/sec)
using PerformanceTest version 4.0 with Corsair DDR2-800.
It takes plenty of funds to achieve a storage subsystem that is
routinely capable of 500MB/second (by comparison).
You can also move your Windows swap file to
such a ramdisk, and it will do I/O much faster:
Windows will "page" programs even if there is
RamDisk Plus version 9 also supports unmanaged
Windows memory e.g. the addresses which XP x32
cannot reach: all recent Intel CPUs are capable
of 36-bit hardware addressing internally.
So, bulk up on RAM: it's cheap right now!
Lastly, it has an option to save and restore
ramdisk contents between shutdown and startup
which eliminates the volatility problem of RAM.
Wow. again, thx for your reply.... to be honest, there are several part of your answer that i didn't understand ( not because the way you explained it, but because of my brain performance isn't as advance as yours...... hahaha.
But thx anyway, thx very much. I'll copy your answer into my pc, and start learn about how it's done.......
The Raptor is quite old technology compared to new drives.
old is not the same as slow. if i want a reliable drive, i'll take a drive with lower areal density (bit density), over one coming off a new production line (less than 3 months old) any day of the week.
given that the 74 GB Raptor is 10K rpm (and that this higher spin speed is reflected in higher functional speed) and has a very good reliability record, well it's still a good product.
i have a 74 GB Raptor as a boot & ap. drive in a dual Opteron system, bought in 2006. also a 320 GB Seagate, in a Core2Duo system, bought in 2007. and a 640 GB Seagate, in a Core2Quad system, bought in 2008. all running 3D Studio Max.
The system with the Raptor holds its own with the Core2Duo system in terms of rendering times - and beats it in terms of boot time and ap. start-up time. It's real hard to tell a difference speed-wise, between the 2 systems on rendering. I could swear the Opteron+Raptor combination is harder to lock up than the Core2Duo+Seagate combination.
It's true that the Velociraptor and solid-state drives are faster than the 74 GB Raptor, but they're also a lot more expensive.
Since you can buy a good 1 TB drive for the price of a 74 GB Raptor, it's a hard choice. I use the Desktop to store files; I would run out of space if I did that with the 74 GB Raptor.