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AHCI and Test Setups

AHCI is a Good Thing

A surprising number of people out there do not realize that in order for your system to see the advantages of Native Command Queuing, changes must be made to the system configuration.  The X25-M is one of the best demonstrations of the gains to be had.  Current Intel SSD owners / potential buyers might want to take note of the following benches.  The huge increase in small file performance makes the effort of switching your BIOS settings to AHCI mode and installing that extra driver on your Windows install well worth the effort.  This is one of those things you want to get right the first time (i.e. before you install your OS).  If you are running XP (and possibly Vista), juggling your AHCI BIOS settings may not work, and will likely cause your system to Blue Screen on boot.  For those sufficiently savvy, PCPer forum moderator Ned Slider has posted a guide for switching to AHCI ‘on the fly’.

X25-M with AHCI disabled (BIOS in ‘IDE’ mode).

NCQ in action (BIOS in ‘AHCI’ mode).

While there are only small gains in large file throughput (near the bottom), there is a 2-3x improvement in small file access.  The drive also ‘ramps up’ to full speed much faster, approaching 250MB/sec when performing random 8KB reads.

Testing Setup

This will not be your typical review article, and as such we did not stick with any single testing machine.  The dynamic nature of the X25-M wear leveling / write combining routines required extensive testing over several months time.  I continued working through an upgrade of my own rig, while Ryan crunched away using his pair of X25-M’s.

Hard Drive Test System Setup
CPU	Intel Q9550	Intel Core i7 920	Intel Core 2 Duo E6400
Motherboard	Asus P5B Deluxe	Asus P6T	Gigabyte P35-DS3R
Memory	4GB DDR2-800	6GB DDR3-1600	OCZ Technology 2 x 2GB DDR2-800
Hard Drive	Intel X25-M 80GB SSD WD VelociRaptor 300GB WD3000GLFS WD Raptor 74GB		Intel X25-M 80GB SSD WD VelociRaptor 300GB WD3000GLFS Western Digital Raptor 150GB
Sound Card	Asus Xonar DX	Asus Xonar D1	none
Video Card	EVGA Geforce GTX 260 Core 216		ATI Radeon X800 XL
Video Drivers	Geforce 180.48	Geforce 181.22	Catalyst 8.3
Power Supply	Corsair 620HX		Antec TruePower 480 watt
DirectX Version	DX9.0c		DX10
Operating System	Windows XP SP3	Windows XP X64 SP2	Windows Vista x64 SP1

My X25-M is retail while Ryan’s are pre-release units.  Any potential differences were negated by the fact that Ryan’s are flashed with the same retail v8610 firmware.

Next Page - Schrödinger's Cat Reborn

Review Index:
- Select - Introduction Background, Leveling, and Combining AHCI and Test Setups Schrödinger's Cat Reborn Intel Option #1: Write Big Intel Option #2: Write Small The Way Ahead / Conclusion