Why do they make it confusing?

[Pierre3400]

I have been looking at buying Ram for my rigs.

I have questions. My new ASRock B75M-ITX, i am running a Sandy Bridge CPU in it, this means im restricted to 1333mhz? or does it mean if i stick 1600Mhz into it (in case of upgrade to Ivy Bridge) it will only run at 1333mhz?

Same question goes for my MSI Z77 BB MPower.
The Specs say: DDR3 Memory 1066/1333/1600/1866*/2000*/2133*(OC), 2200*/2400*/2600*/2667*/2800*/3000*(OC, 22nm CPU required)

This confuses the heck outta me? Is the max i can buy for it 1600, and then OC them or can i get 3000Mhz (that i am) and they will work too?

Im confused about this.

 

[Ajay57]

Here you are my friend the lists of tested Ram for your Boards! AJ.

1, http://www.asrock.com/mb/memory.asp?Model=B75M-ITX
2, http://www.msi.com/file/test_report/TR10_2681.pdf

 

[Anonaru]

I have been looking at buying Ram for my rigs.

I have questions. My new ASRock B75M-ITX, i am running a Sandy Bridge CPU in it, this means im restricted to 1333mhz? or does it mean if i stick 1600Mhz into it (in case of upgrade to Ivy Bridge) it will only run at 1333mhz?

Same question goes for my MSI Z77 BB MPower.
The Specs say: DDR3 Memory 1066/1333/1600/1866*/2000*/2133*(OC), 2200*/2400*/2600*/2667*/2800*/3000*(OC, 22nm CPU required)

This confuses the heck outta me? Is the max i can buy for it 1600, and then OC them or can i get 3000Mhz (that i am) and they will work too?

Im confused about this.

It's all a big meaningless frazzle-- OCing your CPU, etc wil allow faster RAM. The SB processors have a powerful controller, and you'll find that the gains from increasing clock speed on RAM are pretty minimal, especially when you can pinch timings instead.

I've found that faster RAM DOES make a diff. beyond 1333 and 1600, but the amount depends on the task. One type of work I do, I see no change from 1066 to 2400, while another nets me something like 12-15% reduction in completion time from 1600 to 2400.

I think that typically your best bet is to run 1600 or 1866 with extremely tight timings.

Edit: To the questions themselves..

What the motherboard supports is basically beans. If a junky board only supports 1333 RAM, and you have a CPU that can support faster ram (Let's look at c3 AMD Denebs, for example), 99.9% of the time, you can run the RAM at 1600 without any issues whatsoever, considering the memory controller isn't on the Mobo. It is a little more concrete on the CPU-- If it only supports 1333 RAM, then setting the RAM speed higher without also overclocking the CPU will not give you a very noticable gain in..anything.

I always found it funny that SB supports "up to" 1333, but hits its best / most efficient ratio at 1600

 

[dtrunk]

BOTH boards support 1600mhz and is the minimum I would suggest you run at is 1600. tighter timing is nice, though someone did post a review of some 11-11-11 samsung ram that OCs to 2400 though it is rated at 1600. i prefer low CL (9 or 10) and 2x4gb kits.

for the i7 3770k i would suggest a faster ram, and running it at 1866 or around 2k. as stated, thought the SB chip u have is stated at 1333 most run around 1600 and see a marginal performance increase.

 

[Pierre3400]

Ok, but when a stick of Ram is rater 2100Mhz, does this mean it will run at 1600mhz, but will oc stable up to 2100mhz? or would the 1866mhz for my main rig run 1866 out of box?

Im looking at Corsair Vengence Ram

 

[Anonaru]

Ok, but when a stick of Ram is rater 2100Mhz, does this mean it will run at 1600mhz, but will oc stable up to 2100mhz? or would the 1833mhz for my main rig run 1833 out of box?

Im looking at Corsair Vengence Ram

I tend to suggest people buy either minimum CAS 1600 or 1866 RAM-- This gives you a good balance between well-binned and well-priced RAM, giving you more room for tightening, clock speed increasing, etc.

You should be able to run 1866 / 1833 / whatever right out of the box, but you may have to set it as such in the BIOS (It will probably "auto" you to 1333 with SPD timings)

 

[Pierre3400]

I tend to suggest people buy either minimum CAS 1600 or 1866 RAM-- This gives you a good balance between well-binned and well-priced RAM, giving you more room for tightening, clock speed increasing, etc.

You should be able to run 1866 / 1833 / whatever right out of the box, but you may have to set it as such in the BIOS (It will probably "auto" you to 1333 with SPD timings)

I mean 1866 of course. But from what i have understood they all run the same speed, but the rates that the companies state are the clocks they will run up to stable?

But i should be looking for CL 8 or 9? From what i understand the lower those numbers the shorter the search time?

 

[Anonaru]

I mean 1866 of course. But from what i have understood they all run the same speed, but the rates that the companies state are the clocks they will run up to stable?

But i should be looking for CL 8 or 9? From what i understand the lower those numbers the shorter the search time?

All the same speed? No. A stick of 1333 RAM won't run at 2400. They are set at speeds based on their bin, quite similar CPUs. Value RAM running at 1333 with a CL of 9 might not tighten to 7 at 1333 either..

Lower CAS / CLk numbers are always better. Tighter timings lower latency, lower seek / search times, and increase bandwidth just like increasing the clock speed would.

 

[Pierre3400]

All the same speed? No. A stick of 1333 RAM won't run at 2400. They are set at speeds based on their bin, quite similar CPUs.

Lower CAS / CLk numbers are always better. Tighter timings lower latency, lower seek / search times, and increase bandwidth just like increasing the clock speed would.

This is what i would be looking to stuff into my main machine, with space to expand later with 2 more.
Vengeance® — 16GB Dual Channel DDR3 Memory Kit (CMZ16GX3M2A1866C9)

 

[Anonaru]

This is what i would be looking to stuff into my main machine, with space to expand later with 2 more.
Vengeance® — 16GB Dual Channel DDR3 Memory Kit (CMZ16GX3M2A1866C9)

It's not a bad kit, but there's CAS8 kits available as well, just keep that in mind

 

[Knufire]

There's two ratings because there's two parts to memory stability. There's the IMC (integrated memory controller) on the CPU and the TAM itself. Both need to be stable in order to get the RAM stable.

The SB IMC is only rated for 1333 or 1600 or something like that but that's sort of a BS rating, it can go much higher.

 

[Ajay57]

Just a quick question for myself and the members a like if this is on the Ram list for your Mobo, does it mean you can only use that. Yes or No!!! CMZ16GX3M4X1866C9R 4GB 1 Pack. Or you just use want you like and do not have to take any notice at all? AJ.

 

[Knufire]

RAM QVL list is only what the company tested when they released the board and is usually never updated.

 

[Ajay57]

So Knu 6 of one half a dozen of another i see thanks, so just a rough guide only thanks. AJ.