The myth of hyper-threading and the Intel i7 CPU
As mentioned in my previous post, I’m planning on building a new PC. So started my investigation into the magical world of computer components. And what I found is that a processor is not always worth more just because it’s got some awesomely bigger digits and oh-so fancy hyper-threading.
the CPUs in question and the $100 question
Even though I’m building a small-form factor PC, it still takes standard components (mostly). So as part of my search, I’ve been trying to decide which processor to buy. The two fastest ones at the moment are the Intel i5-2500k and the Intel i7-2600k. Well that should be obvious, right? Bigger numbers, so the i7 must be better, no? Not so fast. After doing some research where I look at the differences between the Intel i5-2500k and the Intel i7-2600k, I frankly can’t see the benefit of going with the i7.
For those that are unfamiliar with small-form factor PCs, they are basically your standard tower-style desktop computer, but one where the tower is the size of a shoebox. Literally. The one you can see below is a good example, and it measures 8.7 x 7.5 x 13 inches. It’s wee.
the price of admission
For info’s sake, up here in icy Canada, the i7 will run you somewhere just over $300. Quite a highly priced piece of silicon. The i5 on the other hand, drops to around $200, or just over $100 less. The differences are astonishingly minor for that $100 you’re spending.
the differences between the CPUs – the “magic” of hyper-threading
100 Mhz! Hyper-threading! 2 MB of Smart Cache! Well, that sounds good, right? After all, 100 Mhz is … uhhh something. And Hyper-threading sounds cool, as does that cache stuff that is so smart. Well not really so much, it seems. Read on.
Tom’s Hardware did a rundown of the benefits of Hyperthreading in a CPU (which is the most substantial difference between these cpus), and there almost literally was NONE, except for video/audio de/encoding. Check out all their hard work over here. For info on what Hyper-Threading is and why Intel thinks you should have some, check out what the smart folks who update Wikipedia said about it. Now, the Tom’s Hardware article was based on the last generation of i7 CPUs, mind you.
In a different article, Techgage checked the benefits of hyperthreading on Lightroom (which I use), and there’s pretty much nil benefit there as well.
On top of that, according to Tom’s Hardware, the list of software and games that even support hyper-threading is incredibly short.
So after all this, you may be asking yourself “why should I even care about hyper-threading?“. And that, dear reader, is a damn good question. I will give Intel a small bit of credit here. If you do video encoding/decoding or if you’re into 3D rendering applications, or even heavy-duty audio, that Hyper-threading will make a difference. It is the regular applications that most of us use day in and day out that will see almost zero benefit.
What about the 100Mhz and the 2MB of Smart Cache?
Well, that proves to be somewhat bunk as well. When the CPUs first came out, there were reviewed at a variety of sites, all far more reputable than this one. For instance our northerly neighbours at Hardware Canucks put both of these CPUs through reams of extensive testing in their i7 2600k and i5 2500k review.
As you can see in the below chart, with all other hardware being equal, the two processors produce practically identical results.
image credit: Hardware Canucks
The reliance on assumption
I think that’s the main reason people keep buying the 2600k. I had assumed it must be better in some way, and that assumption nearly cost me $115 + tax. Thankfully I did a bit of research to discover how minor the difference is. I just saved myself a bunch of money – you should too.
One Response
well, i didn’t save the money because i never even stumbled across anything hinting at that whole HT-issue until i started overclocking my 2600K right now and read lots of articles on it. and even then, only after hours of reading and trying stuff out, i stumbled across the fact that HT makes keeping things cool more difficult.
and if you take that in mind… because… at least i assume most people who get 2500k or 2600k will want to get the most out of it, especially since you can overclock them a lot with just minor voltage adjustment.
and one should consider that when talking about the benefit.
my 2600k without HT runs fine so far at 4.5Ghz. but with HT, there was so much heat that i probably would have had to use something like 4.2Ghz instead.
i’m a 3d artist – though i play more on this machine than i work, so rendering is the second most important thing after regular use and gaming. 3ds max saw a 10% benefit in that tom’s hardware article. if you take into account that you can overclock ~7% higher while having the same temperatures, that casts quite a different light on those results. even more so when it comes to regular use or gaming. there, it doesn’t just neutralize the benefit of HT but you’ll have the advantage without it.
by the way – that hardware canucks image has such shitty quality that one can’t read anything… do you not check your articles after you publish them?