dual channel, with > 2 DIMMs

[D.P.]

Been out of hardware for a few years and now I'm a little confused.

I'm thinking of buying an i5 or i7 (1156) setup.

Default option is 2x2Gb ram. But I'm wondering if I will need more for future proofing.

I know 2x2 will run in dual channel mode, and dual channel mode will basically double bandwidth (like a HD RAID setup).

But what happens if you put 3X2 or 4x2GB dimms in?
with 3x2 dual channel do I get 2x2 in dual channel and 1x2 in single channel mode, or will all dimms run in single channel mode? with 4x2GB will I get 2 times a 2x2Gb dual channel setup?

What is the performance change from 2x2Gb going to 3x2Gb.


I mostly use Photoshop, lightroom, movies, DTP, and some gaming

 

[D.P.]

Was thinking of an i5 or i7 860 inthe 1156 chip, with a P55 motherboard. I don't really want to pay the extra for the 1336 motherboards.

I was thinking of just the i5 750, but realised I could spend 60 quid more and get the i7 860. This wont take tri-channel memory. I then wondered what the performance difference would be between the i5 with 8Gb of memory of the i7 and 4Gb of memory as they should cost the same. A half way solution is the i7 860 and 3x2Gb of memory but this wont run in a tri-channel setup.

I could get the I7 940 and 3x2Gb but this will require a £40 more expensive motherboard. Then it is all just a bit too expensive and I would prefer the basi i5 setup.


So I guess the real question is, what is the performance cost of not running in dual channel mode if 3x2Gb were used?
Also would it be possible to upgrade from a 2x2gb now and adding 2x2 or 2x4gb later?

 

[D.P.]

Somewhere around 400-500 ideally, but I want to know my options if I spent a little more.

Given I have a few components, this doesn't include a monitor and I only need a mid end GFX card I was going for an i5 750 and 2x2Gb ram with cheapest mobo. £70 extra would buy an extra 4Gb of RAM or the i7 860. I was wondering which if either are really worth it.


This will mostly be for photoshop, lightroom, HD movie palyback and some video editing.

 

[D.P.]

Just a tower, No OS, I have a case, and I excluded DVD although I might buy a blu-ray drive later outside of this budget.

Really it is: CPU + Memory + Mainboard + PSU + HSF (if needed) + mid-end GFX card + 500-1000GB HD.

 

[D.P.]

Thank you for the build spec.
I was thinking more along the lines of:

Intel Core i5 750 2.66Ghz (Lynnfield) (Socket LGA1156) - Retail £159.99

Gigabyte GA-P55M-UD2 Intel P55 (Socket 1156) DDR3 Motherboard £86.99

XFX ATI Radeon HD 4830 512MB GDDR3 - Retail £75.99

G.Skill Ripjaw 4GB (2x2GB) DDR3 PC3-12800C8 1600MHz Kit £67.99

Western Digital Caviar Green 500GB SATA-II 32MB Cache - OEM £39.99

Total: 442.44 Plus a £50-60 PSU
bringing it to £500


Now, I could pay the £67 to get the i7 860, or pay £67 to get an extra 4Gb of RAM.
I will also be buying in Switzerland so my prices are actually cheaper here.




Q) If I have 4x2Gb ram, will it run in dual channel mode??