OC a 2700k or 3770k on z77 for gaming rig.

[Xaanix]

I recently bought 2 EVGA gtx 680 SC Signature cards, they're great but as anticipated they're not being fully utilized because the rest of my system is a bit old.. (currently running an i7-860 at stock frequencies)

So now i'm in looking to upgrade the rest of my system!

Looking at the market right now i have some difficult choices to make.. Mainly, whether to go with ivy bridge or sandy bridge. I looked at sandy bridge-e, but ruled it out because there are no unlocked processors near the 300$ range, and hex-core processors arent really needed for gaming.

Looking at some benchmarks between 3770k and 2700k, it seems that when both machines are given a healthy overclock (an overclock suitable for daily use), the 2700k ends up outperforming the ivy bridge in games even though clock for clock the ivy bridge is more efficient.

Am i crazy for wanting to go with a z77 motherboard and drop a 2700k in it?

I'm anticipating being able to get a 2700k up to 5GHz using a H100 (if i can get it to fit in my cosmos S, I will)

My current plan is to get the ROG Maximus V Formula Z77 board once it's available, with 16 gigs of ram (recommendations welcome on the ram, was thinking of getting ripjaws since they are pretty reasonably priced and high frequency)

Am I correct in assuming the Formula board will only do 2-way SLI and not Tri-SLI? (i'd prefer to have the option to do Tri-SLI if possible but it's not worth 100$ to me in order to do so.)

My last concern is about PCIE bandwidth.. does each PCIE 2.0 x16 lane have its own bandwidth or is all the bandwidth on the bus shared? Am I in danger of saturating the bandwidth of pcie 2.0 x16 with a gtx 680? What about with 3 cards? (some motherboards do x16, x16, x8 i think, when 3 cards are plugged in)

I'm a little nervous about giving up pcie 3.0 by going with sandy bridge...

What do you guys think?

[Zka17]

Just one thought... if you want to go with heavy OC (5GB is getting close) on a H100, you will have to have a damn good airflow...

If I would be you, I would feel better combining the H100 with the 3770k (22nm technology, TDP=77W) than with 2700k (32nm, TDP=95W). At those high OCs you won't feel the difference between them... :cool:

[Xaanix]

My case is a Cosmos S, if i find i cannot fit the H100 in it (still haven't found evidence either way online) then i will probably get a HAF X case to replace it. My Cosmos S has 7 Case fans (1 200mm, 6 120mm) on a fan controller. Overall, the cooling is pretty Good. Besides, the H100 would exhaust all the heat out the top no?

The reason i'm worry about ivy bridge is because of the temps... to run a good overclock like 4.7, the temps are really high (around 90C). I really don't want to run this hot, and my thinking is that i could run a sandy bridge 2700k which is easier to cool at temps much closer to 70C (i'm thinking i dont want to be above 80C during stress testing, and 70C while gaming).. I"m not exactly sure if i can get those temps on a 2700k at 5GHz, but i'm pretty sure whatever temps i'm able to achieve on the 2700k will be way better than what i can get on the 3770k. I'm guessing that the 2700k will benefit alot more from the H100 than the 3770k which will allow a much better overclock, enough of one to surprass the IPC gains of ivy bridge.

Somewhere i saw benchmarks between 2700k and 3770k, both OC'd for various games, and the 2700k beat the 3770k in nearly every game.

[Xaanix]

http://www.youtube.com/watch?v=c6zUE-dlPfs

This guy has some benchmarks at the end, showing basically that the 2700k when overclocked to its potential beats out a 3770k clocked to its potential.

His conclusions which i've seen elsewhere are basically:

If running at stock clocks, go ivy bridge
If overclocking to the max potential of the chip, sandy bridge is better

[Zka17]

Oh, I forget this issue: http://rog.asus.com/forum/showthread.php?16151-Reason-behind-high-overclock-temps-on-Ivy-Bridge&coun...

Based on that, I changed my mind... Even the lower (22nm) manufacturing technology and the subsequent lower TDP, the Ivy Bridge seemingly is running hotter because of its thermal design.

So, go with 2700k! 😄

As for the case, design the airflow carefully... for 5GHz with H100 also consider a push-pull fan configuration...