Dual core systems again

I've just upgraded a system from a Pentium 4 3GHz to a 'cheap as chips' Celeron E3200 (see previous posts) and what a difference it has made. Both these CPUs were slightly overclocked by 15% to 3.3GHz and 2.77Ghz respectively. Some preliminary testing showed that the integer performance has gone from 8,017 to 21,179 (Sisoft Sandra Arithmetic), an almost threefold amount.

I view the more general PCmark05 type of benchmark as more representative measurement of a system's responsiveness however. It shows weaknesses and bottlenecks in a systems configuration. Here then the difference was even more amazing from 2,280 to 6,328. Again an almost threefold improvement. Just by changing a CPU to one of the cheapest modern ones available.

I used to think that adding memory to a PC was the easiest and most cost effective way of improving an older system's performance. The computer equivalent of a mid-life upgrade. Though it is still effective upgrade, memory costs have gone up considerably in the last few months and now a cheap dual core CPU upgrade to those Socket 775 systems looks an even more effective alternative.

A cautionary tale

One of my customers gave me his Fujitsu tower that was giving him trouble after I installed his new DELL. It was only a couple of years old and had a reasonable spec. So I thought that by replacing the scruffy old case with a new shiny black one (£16), an a extra stick of 1Gb DDR memory (£23), SATA DVD writer (£18) and a better 400W PSU (£17) should fix the problem and make it resaleable. I was wrong it continued to crash indicating that the strange Fujitsu version of an Asus motherboard (P5SD1-FM2) was the culprit. Interestingly this had been replaced just recently under the extended warranty but was still giving problems. It was an Intel socket 775 with DDR memory which is also a bit rare.

So I replaced it with a cheap Asrock motherboard (£31), and two sticks of 1Gb DDR2 memory (£35). Because the Windows XP installation was keyed to the old Fujitsu BIOS, it needed a new copy of Windows 7 (one of my preordered £45). The Intel Pentium 4 3Ghz CPU was a bit weak but at least the system worked reliably. All was well for a while, but I wasn't able to sell it.

Then another customer gave me an overheating DELL 5150C SFF computer with a passively cooled Radeon X600 graphics card and an Intel Pentium D 3GHz dual core CPU. I removed the graphics card and used the integrated graphics, but it still ran warm due to the powerful and hot CPU. I then decided to swap the CPUs in the two systems. The DELL accepted the single core Pentium 4 CPU without a murmur and was a lot cooler. Then I put the Pentium D onto the Asrock motherboard and mounted a good size Akasa fan (£10) on top to take care of the cooling. It ran for about 10 seconds just booting into Windows and stopped. No lights, no fan, no power and a faint acrid smell of burnt electronics.

I checked the power supply, no problem. So I'd blown the motherboard. Upon checking, the Pentium D 830 was not on the approved CPU list as the motherboards maximum TDP was just 105W. As are most cheap Socket 775 motherboards. Pentium D's are probably the CPUs with the highest TDP ever and are certainly way over 105W! So I have now bought another motherboard and CPU. This time an Asus KP5QPL (£38) and a new Intel Celeron E3200 CPU (£35) to get the computer going again.

My exploits have cost a total £268 and I'd have been better off if I'd have just bought a new, faster DELL with a warranty and be easier to resell. Let this be a lesson to us all that resurrecting an old system is often definitely not worth it.