Processor Upgrade

[#1]

I am thinking of upgrading my processor.
I currently have a Gigabyte M61P-S3 Motherboard with 2GB RAM and the AMD Sempron 3400+ with just over 1TB of HDD between PATA & SATA drives.
Will I get much speed increase (especially with video encoding) if I upgraded to an Athlon 64 2x 5200 Dual Core AM2 2.7GHZ 1MB Cache processor?
Also, if I were to upgrade would I need to re-install XP?
Thanks

[#2]

Yes to the first question
No to the second.
Your current processor runs at 2GHz. The new one at 2.7GHz which gives a 30% improvement straight away. The new one also has more on-board and faster cache & a faster internal bus so is a much faster number cruncher that the Sempron, which is basically an entry level (i.e. cheap) processor.
Also depending on what software you use, it could make use of the 2 processors compared to the one in the Sepron so speed could increase again by a factor of 1.2 -> 2.

[#3]

Thanks for the advice.
Pretty much confirms what I was thinking.
Does anyone know if Ebuyer is reputable for OEM processor chips? Are they brand new?
Cheers

[#4]

Well I've not had any problems with ebuyer, but have heard some horror stories. I prefer to shop at http://www.aria.co.uk these days, they have fantastic customer service and are one of the cheaper online stores to boot.

[#5]

I tend to use Scan as my first port of call - it helps that I get free postage