CPU speed is not the only thing that speeds up a computer. Hard drive speed, memory, bus, cache etc. will all still be the bottlenecks in an old 4550 and going up to 3.06 would not make much difference. I don't know if the cpu would work, but you should always have the latest (and last) bios when doing upgrades.

Hyperthreading isn't much of an advantage -- and in fact can actually slow things down vs. keeping the setting turned off.  Many games and some video apps actually run slower with HT enabled - in all, it was a poor substitute for a true dual-core CPU and very little software remains that can benefit from HT.  You just won't see much, if any boost from the 3.06 vs. the 2.66 - and none at all from HT.

It's not worth spending the $50+ on.

Thank you Mary for your reply. The CPU upgrade is only one of several upgrades that I am making to this old workhorse of a desktop. I want to maximise the CPU possibility as I have found a very modestly priced working model (£20) which will give me the benefit of HyperThreading which my present 2.66 model does not.

 I have increased memory and plan on changing the video to an ATi model from my present Nvidia FX 5700 as certain Ati models support Avivo technology which will be useful in speeding up my use of the computer for video file conversion as it uses the onboard hardware for the conversion as apposed to (the much slower) software only that I am presently using.

Shaun

Borland Interbase was one application that ran much faster with HT turned off.

Extra memory, a faster hard drive, and a modern video card are good choices to boost a 4550's throughput.

You'll not see a noticeable overall increase short of installing a 10,000 rpm Raptor - which will require a controller card -- and at that, it won't do much overall.  The P4 architecture is just too old and slow for anything to appreciably boost its overall performance.

OK, so the 3.06 is no better than the 2.66 I already have even though Windows XP  takes advantage of HT. Hmm..I will ponder that one.

The hard drive is a more difficult one as the 4550 does not accept the SATA models, only IDE/UltraDMA drives. Do you have any particular models in mind that would give me a noticable increase over my present 120Gb 7200 HD?

Shaun

OK, so the 3.06 is no better than the 2.66 I already have even though Windows XP  takes advantage of HT. Hmm..I will ponder that one. The hard drive is a more difficult one as the 4550 does not accept the SATA models, only IDE/UltraDMA drives. Do you have any particular models in mind that would give me a noticable increase over my present 120Gb 7200 HD?   Shaun

Yes -- do what I did with my 4550 and install a Syba 150R SATA card (or equivalent) and use a SATA drive.

>....Yes -- do what I did with my 4550 and install a Syba 150R SATA card (or equivalent) and use a SATA drive....< 

Ooh, that sounds interesting. Was it expensive for the whole lot?

I see that Dell are now officially supporting the use of 1Gb memory modules (PC3200 400). See here:

http://accessories.dell.com/sna/PopupProductDetail.aspx?c=us&l=en&cs=19&sku=A0740408&price=47#Overview

The reviews seem to be very much in favour.

Shaun

Yes, I agree with that. However, you will be able to install 2Gb of ram for use with Vista/Windows 7.

Incidentally, the upgrade of the Bios to A08 was absolutely painless, thanks to Dell's very easy implementation of it within Windows.

Shaun

While you may be able to install PC3200 RAM, it won't run at PC3200 speed - there is no 800 MHz bus support in this model;  the RAM will downclock to 533 MHz.