worth the upgrade ?

Intel Pentium 4 531 “LGA775 Prescott” 3.0GHz (800FSB) with HT Technology - Retail


Intel Pentium D 925 / 3 GHz ( 800 MHz ) - LGA775 Socket - L2 4 MB ( 2 x 2 MB ) - Box

am I going to see a noticable improvement ?

“worth” depends on the cost. If something dislikes HT, then you can get up to double performance. If it like HT, then it’ll be less. The 925 has double the cache per core, compared to the 531, which is nice.

If the 925 is cheep, why not. It’s on 65nm so power consumption isn’t double. TDP is only slightly higher.

£64.00 for the chip , plus I can ebay the other one