http://ark.intel.com/compare/65512,65511

The only difference that I'm aware of between these two CPUs is the lower base clock speed and lower TDP of 2.8 GHz vs 3.1 GHz and 65W vs 77W for the i5-3450S vs the i5-3450. The two processors are currently selling for essentially the same price (~ $200).

I don't fully understand how turbo speed boost works on these newer Intel CPUs. Would you likely see any real world difference in performance between the two and would it be worthwhile in constructing a quiet PC to use the S version? The most power hungry task that I perform is video editing.

What woud be a moderately priced quiet CPU cooler to be used with either? Probably not passive given that it will be in a microATX case with only a single low speed intake and a low speed exhaust fan.

When doing lighter things the regular 3450 will downclock itself (per default BIOS power saving settings) quite handily so for that kind of system I wouldn't bother with the 3450S, just in case the little extra oomph comes in handy on a larger video job. However, in case the video software could take advantage of the Intel "quicksync" feature there might be a cause for getting the 3570K model, as the HD2500 graphics part in the other models seems to be much slower. Consulting experts on that particular video software might be wise.

Without adding a separate graphics card of any significant TDP the cooling situation will be easy. If quiet operation during video work is wanted, a third party CPU cooler would be a good idea. For instance the Scythe Samurai ZZ is a both small and relatively inexpensive option.

The Samurai is also potentially a somewhat dangerous heatsink because it interferes with normal cooling of the part of the board surrounding the CPU area.

Check SPCR's reviews and recommended list for other suggestions.


As best as I can determine, assuming adequate cooling the two CPUs have the same single-threaded performance but the 3450S has slower multi-threaded performance.


Some people would see a difference and others wouldn't. It depends mainly on the work you want to do.
Let's put it that way: if you wouldn't experience a real-world difference, why are you buying a non-K quad-core?
There are better choices if you want single-threaded performance such as the old 2500K or one of the newer dual-cores.

With both of them having the same max turbo speed of 3.5 MHz, wouldn't they have exactly the same 'oomph'?

Not following what you're saying there. Maybe it's the double negative.

I haven't seen any reviews for the "S" version. So, this is just guesswork.

There is a fair bit of leeway on TDP and it tends to promote a family of products for market differentiation rather than what the parts actually consume under heavy load. The std 3450 might actually fit into the 65W category. They might lower the core's voltage at load by 0.1V to fit into the 65W TDP. <shrugs>

Chances are, you could just buy the plain 3450, adjust the core voltage by 0.1V or so in bios, and meet the same load power as the S version while having the faster non-turbo clock rate.

faster clock = higher load power


You didn't quote the explanation but it was there.
I asked this question because I don't understand how you came to settle on those two CPUs and because I'm questioning your ability to pick your CPUs yourself.
There's nothing wrong with not understanding the issues involved. Most people don't have the beginning of a clue.

I'll make it simple: if you want "oomph" at that price point, pick a 2500K and a board which supports overclocking (they've become quite affordable).
You can have better "oomph" if you pay a bit more obviously.

The point of the 3450 and the 3450S is that they're among the most efficient x86 CPUs on the planet. But they're don't offer the most "oomph" for the price.
If you give a CPU more "oomph", you make it less efficient. That's the only reason to pick the 3450S: it's got a bit less "oomph" by design, which makes it a tad more efficient.

In case you're wondering, "oomph" only means "phat benchmarks" and not necessarily "something I have a use for".

Uh, thanks. Maybe you can help someone else.

The turbo does not kick in when all four cores are fully loaded like in a video encoding situation. It's also possible that the turbo function behaves somewhat differently on these low-TDP variants in order to keep within limits, although I suspect that the lower normal core clock is the main reason for the ability to lower the power envelope(TDP) here.

A better way to look at this is that both chips idle at about the same wattage. The difference comes in those uncommon moments when you put a load on them. When you do, the 3450 will carry a heavier load (ie. do more work) and generate a bit more heat.

+1
Well said, but you somehow left out oomph definitions. Helpful not??