DDR3-2133 CL11 or DDR3-1600 cl9?

[gcb]

I don't care much about the price difference ($20) and I will use the system mostly for compiling and emulators (not games but things like qemu, android emulator, etc)

I will probably go with a i5 3570k

i'm now between a
Vengeance 8GB DDR3-2133 (PC3-17000) CL11 Desktop Memory Module Kit (Two 4GB Memory Modules)
and a
Vengeance 8GB DDR3-1600 (PC3-12800) CL9 Dual Channel Desktop Memory Kit (Two 4GB Memory Modules)

They are $60ish. ($55~70)

I'm also open to suggestions. I will probably not overclock the system as from my experience this is more trouble than it's worth (face it, overclock is not saving money, it's a hooby


---
edit, i'm trying to understand what CL means in real life... it's the amount of cycles wasted to get one row of data if I understood the FAQ correctly... so on one memory i will waste
9 cycles, from 1600/sec
so in one sec it has 1600 whatever-a-ram-does
i have to waste 9 to get data.
that translates to 177.7 data requests per second.

on the other
11 cycles, from 2133/sec
that gives me 193.9 data requests per second.

does this logic even makes sense?

it would be an ~8% increase, which is not seen here, at all, http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3/5
those graphs show ~3% from DDR1600 to DDR2133. And they are comparing DDR2133 CL9! which should be even better.

---
Q2:
Also i remember from a long time ago (when CL was called CAS) that cheap chips would have things like 2-2-6 and good chips would have something like 2-2-2, but both would be marketed as CAS-2

those Corsair chips are 9-9-9-24... does this mean CL9 is snakeoil for this brand?

 

[Jay-Z]

Honestly, 1600MHz CL9 is the standard RAM configuration. Sure, you should get slightly (~9% theoretical) more performance from the 2133 CL11 RAM. However, that really won't make much of a difference in real world scenarios and even some bench-tests.

That link you posted is quite helpful and you can see how close the results are. I am running 4x4Gb 1600MHz CL9 Corsair Vengeance in my machine and I am quite happy and do not regret not getting the faster RAM.

 

[gcb]

I see you have an i7, so for me even the 1600 may be too much... i'm trying to understand the ram 1600 thing... i don't think it's even supported on most i5 chips...

http://ark.intel.com/products/52207

"Memory Types DDR3-1066/1333"

So even if the board forces the ram to be faster, the CPU will probably not run faster just because the mobo+ram wants it to... unelss you overclock the CPU, DDR3-1333 is the best i can go.

Or am I getting this all wrong?

Edit: wait, you chipset has the same RAM limits than the chip i'm considering... so, which frequency are you running yours?
http://ark.intel.com/compare/52214,52207

 

[gcb]

Ok, understood where the 1600 get's in... in the new i5 models

http://ark.intel.com/compare/65520,52214,52207

but i'm still wondering how your i7 and the ones tested on the link in my first post could benefit from anything >1333 without overclocking the CPU frequency...

 

[Jay-Z]

You just change the DRAM frequency setting in the BIOS and the RAM runs fine at 1600MHz. I wouldn't get RAM that is mush faster than this though.

This may be of help:
http://www.tomshardware.com/forum/315969-30-2600k-runs-1333mhz

Does that answer your questions?

 

[RetiredChief]

OK
For the IB, i5 3570 DDR3-1600 would be the best choice. For IB (ie i5-2500k) DDR3-1333 would be the proper choice.

For SB, DDR3-1333 is the specification and running ram above that speed is considered OCed (If if the CPU is not OCed). This invalidates the standard Intel warantee. Hoever for 20 bucks Intel wil sell you an OC warantee.
For IB the Ram spec was raised to DDR3-1600.

Also Both SB and IB have a max Ram voltage of 1.575 V.

Myself, I'm running Ripjaw DDR-1600 CL 7, 1.60 V with my i5-2500k

PS - Outside of benchmarks there is not a big performance boost above DDR3-1333. the real world performance gain in lower CAS ratings is even less noticable.

 

[k1114]

The speeds listed on the intel site are stock speeds. With SB and IB the ram speed is not connected to the cpu speed so you can oc the ram without touching the cpu speed and vise versa.

 

[RetiredChief]

Memory controller is ON-Die with IB and SB. While it is true you can change the Ram speed without adjustimng the BUS Freq, thus not effecting CPU speed - Intel has come out and stated that for SB and IB that running your ram above the spec is considered Overclocking even though the CPU is not overclocked.
AND the sale a Overclock warranty to cover both OCing the CPU or the Ram, or Both.

Ref: http://www.anandtech.com/show/5442/intels-performance-tuning-protection-plan-warranty-for-overclockers

 

[maestro0428]

Don't waste your money on faster memory, it will make absolutely no difference in real world applications. Many benchmarks have shown that.