Well, you didn't mention a video card. Or are you using the onboard? I honestly wasn't expecting you to go for such a 'modern' processor, do you really need that much power?

EDIT: I just noticed your sig! We should really compare our P3 450 machines sometime. Mine is just overclocked, but they are pretty similar. I'm using a 440 chipset as well.

I am focusing on core system at the moment. Video card and sound card are not in the mix right now. Hmmm, do I need that much power? If I dual boot then definitely and what's wrong with having more power? Remember, it also has less power by easily being able to underclock.

Cool, that system is up on a shelf currently and will be replaced by my new DirectX 7.0 build.

The main benefit of the i5-3570K might not be its speed but its underclocking potential. I have been reading that some XP games might not like an extremely fast CPU and having an unlocked multiplier can easily solve that.

Not necessarily. If the problem is the reported speed by time stamp counter (RDTSC) then Intel's invariant TSC implementation can be a problem. From the Core2 (and up) TSC always reports the frequency linked to the maximum performance state regardless of speedstep's actual clock or the reduced multiplier set in BIOS. The last CPU generation that is flexible in this regard (but uses invariant TSC) is Phenom 2 from AMD. With a trick the TSC is resettable on Phenom 2 at runtime to any clock frequency that is programmed into the P0 performance state. Unfortunately on Bulldozer/Ryzen the required MSR field has become read-only...
http://falcosoft.hu/softwares.html#phenom2_tweaker
NFS 5 is an example that has this TSC bug above 2 GHz.

Interesting. I'm going to read up on that.

EDIT:

Wow! The AMD Phenom II X6 1100T is pricy!

squareguy wrote:

The Ivy Bridge i5-3570K is about as fast as you can get without getting exotic (socket 2011). Fast, no hyperthreading, and the price has come down a lot. The main benefit of the i5-3570K might not be its speed but its underclocking potential. I have been reading that some XP games might not like an extremely fast CPU and having an unlocked multiplier can easily solve that.

The i3-3220 I have here is not a K version and cannot overclock. however, it can downclock from 33.0x to 16.0x and everything in between.
Hyperthreading can be disabled, and the second 'real' core can be disabled as well. This is on a Gigabyte Z68 board, these options are in the Award BIOS. I don't really use these settings, but they are there, and they seem to work.

Wow! The AMD Phenom II X6 1100T is pricy!

Yes, but X4's prices are much more friendlier. (and many Zosma X4 can be unlocked to X6).

The i3-3220 I have here is not a K version and cannot overclock. however, it can downclock from 33.0x to 16.0x and everything in between.

Would you test your i3 with 16x multiplier to see how its TSC behaves? You can use my tool (it's only 4KB and no installation is required).
http://falcosoft.hu/softwares.html#tscwin
I have only tested Core2, Atom, and i5 chips, but all of them reported always the clock frequency of the maximum performance state.
BTW all Phenom 2 chips have an unlocked multiplier from 4x (800MHz) to their factory default, and black edition ones also have unlocked multipliers from the factory default to 35x.
Also cores can be disabled even without BIOS support (or entering the BIOS) at runtime with the help of K10stat's downcore feature (a warm reset is required).

Falcosoft wrote:

Would you test your i3 with 16x multiplier to see how its TSC behaves? You can use my tool (it's only 4KB and no installation is required).

Of course. Here are the results at 16.0x multiplier (Both cores enabled). Seems like good news right? Just that 1600 MHz is not particularly slow.

Yes, it is good!
So the problem seems to be more complicated than I originally thought and may depend on also MB/chipsets.
In problematic cases, like my currently testable Core2 Duo E7500, despite BIOS forced reduced multiplier to 9x the reported TSC clock frequency corresponds the default 11x multiplier: