no, with PCs you need to ensure all bottlenecks are catered for so need ram, faster processor, good speed hard drives etc, upgrading one doesnt mean the others will keep up.
I've decided I'm rebuilding the office computer and using some of the bits from it for the new system. Could I ask you to take a look at this spec and advise any improvements?
New Parts Case: QUARTZ II 4BAY 450W BLK/SLV USB/AUD/LCD (£32.00)
PSU: 450W (Included with case)
Motherboard: Asus 780a SAM2+ DDR2-1066 3xSLI OBV OBS 2xGbE (£124.35)
Processor: Intel Q9450 C2QUAD 2.66GHZ S775 1333FSB 12MB (£178.45)
System Disk: Western Digital 150GB VelociRaptor 10,000RPM SATA 16MB (£110.99)
Existing Parts: 4 x 1GB Supertalent DDR2 667 MHz Ram
2 x ATI FireMV2400 PCIe 128MB Graphics Cards
1 x Samsung 160MB 8MB Cache 7200rpm SATA Hard Disk
1 x Hitachi 250GB 7MB Cache 7200 rpm SATA Hard Disk
1 x Seagate 250GB External Backup Disk
DVD writer/Card Reader/Floppy etc...
Windows XP Pro 64 Bit