I built a desktop computer probably about 8 years ago when the first series of i7 processors (i7 920) were released. I pulled this out of my dusty cupboard yesterday where it has sat unused for about 4 years.
I am interested in possibly building a new PC soon, and so I have started researching various components.
I noticed that my current system supports both hyper-threading and triple channel memory. Most of the current intel CPU's seem to fall into one of 2 categories.
They are either about the same price as I bought my i7 920 for (I think about 250 GDP) and have dual channel memory and often do not have hyper-threading.
Or they are significantly more expensive and have both hyper-threading and quad channel memory.
I wonder why it is that CPU's are being manufactured without hyper-threading considering that technology has been around for quite some time. (My understanding is this is an intel only patented technology, however.) But this is not my main question.
I want to know how do current intel CPU models perform compared to my i7 920.
My expectation is that even though I have triple channel memory, my memory clock is either 1066 Mhz or 1333 Mhz, and current DDR3 clocks exceed 2 Ghz. DDR4 modules I have seen start at about 2 Ghz. Therefore I expect modern dual channel configurations probably produce about the same memory bandwidth performance if not more.
Current intel CPUs clock about 3.5 Ghz stock, whereas my CPU clocks at 2.66 Ghz stock. Naively higher clock is faster, but does the performance vary with and without hyper-threading?
My question comes down to should I invest money upgrading my system? (Since this is perhaps subjective, what I really want to know is measurements of the performance difference.) And most importantly, are there any benchmark tests which compare older i7's to current i7's?
Subsequently Added Info
I will be using my system for data processing. Typically this involves a small number of CPU operations on large (~ 6 terrabytes) quantities of data. As a consequence, performance is usually limited by memory bandwidth and disk bandwidth.
Disk bandwidth is typically a problem which you can either deal with in an effective way by changing how your code works (eg; parallelize it so less time is spend loading data from disk), or you can't deal with at all.
Memory bandwidth is subject to a large number of things. In my experience, 3 channel memory will ensure exactly 3 times more bandwidth than an identical system in single channel mode. I would assume intel have reverted to average consumer CPU's being dual channel because most users, even gamers, probably do not run up against memory bottlenecks in the everyday use of their computers. Having "more megahertz" in your RAM is often only useful if your CPU/motherboard combination can run at those higher speeds. For example, the motherboard I am using with the i7 920 has memory speeds of 1066 / 1333 Mhz, and up to 1866 Mhz as "overclock". But I could never get anywhere near that. 1333 was sometimes a challenge, and the memory I was using was rated 1600 Mhz...
I found some info here which compares intel i7 920 to 6700K and 4790K.
But the info on this website makes no sense. They conclude that they recommend the 6700K even though it performs worse in single process and mutli-process tests. I personally do not think this is a reliable source.