3550 = #57 CPU - 7673 points
3570k = #58 CPU - 7665 points
3450 = #64 CPU - 7157 points
These points are basically processing tasks completed in a set time, so they are pretty much directly comparable.
Mind you, this is only one program and it isn't perfect.
It still does show that the 3550 is just as good as a 3570k at stock speed for the most part. The 3450 is significantly worse, but still quite good overall. The 2500k is the gold standard processor and that is #75 with a score of 6740 at stock speeds.
Ignore PassMark and any other synthetic benchmarks, they have a tendency to be inaccurate for CPU ranking purposes. It's better to look at real application benchmark then average them out to get a truer sense of how the CPUs performs.... unless of course the sole purpose of the PC is to run synthetic benchmarks and nothing else.
Yes, the i5-3550 will give you virtually the same CPU performance as the i5-3570k. There is only 100MHz difference at stock speed which is miniscule.
The difference between a 3570k and a 3450 is about 50-60$. Not a whole lot, so if you are going to buy a very powerful pc, you might aswell use those money for the 3570k and have the feeling that you can overclock it anytime you wish .
should i save a few extra dollars and just get the 3450?
All i5-3xxx are nearly the same at stock clock except for the T/S models. The decision really comes down to whether or not you think you might need the extra 5-10% stock performance and that the price premium is worth it.
At my local shop, the 3450 is over-priced at $200 while the 3570k is at Intel's launch list price of $220 so if I had to build a new i5-3xxx PC tomorrow, the 3570k would be quite tempting except for requiring a z75/z77 chipset to unlock overclocking which means spending ~$30 more on the motherboard.
Ignore PassMark and any other synthetic benchmarks
How about instead of trash talking benchmark X with nothing to back it up, you instead provide an alternative better benchmark to use instead. That way you wouldn't waste everybody's time like you are doing now.
Also, quit using stupid words like "synthetic". They don't give more weight to your non-backed up statements like you think they do.
Also, its pretty stupid to contradict the Passmark benchmarks by saying the exact same things the benchmarks say. If you are going to say that Passmark sucks, you at least have to say that Passmark is wrong for reason X or else you sound like this:
Passmark: "The 3570k is about 1/1000th different from the 3550"
You: "No, the difference is miniscule".
Passmark: "And the difference between 1/1000th and miniscule is what exactly?"
You: "Uhh, hold on while I try to find a "real world" benchmark that proves the difference is miniscule".
Passmark: "Why are you wasting your time right now when I already showed the difference is "miniscule" as in 1/1000th?"
You: "Because I like to use buzzwords to try and sound intelligent".