DDR2 1066 vs. DDR2 800

[Anunnaki]

I'm trying to make a decision about which speed of RAM to buy. I'm about to upgrade my RAM and motherboard, and the new motherboard's rated for DDR2 1066. But a lot of the reviews for 1066 RAM on NewEgg say that it's basically just DDR2 800 RAM factory overclocked to 1066 MHz. A lot of people were saying their 1066 RAM defaulted to 800 MHz and they had to OC it themselves.

So, I'm wondering if I should just buy DDR2 800 RAM and OC it to 1066. But that just seems kind of weird to me to buy slower RAM with the intention of OCing, compared to buying RAM that may be designed in some way to handle 1066 MHz natively.

What do you guys recommend? Buy 800 RAM and OC, or buy 1066 RAM?

 

[Moose]

If you want 1066 buy it, I got some 800 and it defaulted to 667, which I of course oc'ed

 

[KBD]

What about your current RAM, Ballistix are supposed to be good overclockers. But of course it depends on the DDR2-800 RAM not many kits are capable of reaching 1066Mhz. If you are buying a P45 or X48 mobo that supports DDR2-1200+ i think DDR2-1066 or higher may be worth it.

 

[Anunnaki]

Well, my current RAM is 4x 1GB sticks of DDR2 800 Crucial Ballistix, but they all somehow crapped out overnight. I thought it was my mobo at first, so I just bought a new one on Friday, but just today found out it was my RAM that was the problem (oh well, new hardware is always fun ).

I thought it seemed kind of pointless to buy 1066 RAM if it's just 800 RAM factory OC'd,but apparently DDR2 800 RAM is the same way? In which case, I'll just go for the 1066.

 

[Asylum]

Get the 1066 ram...If you have to overclock it...it will still be faster than 800 rated.

 

[Anunnaki]

Thanks, I got the 1066

 

[Mussels]

let me put it into perspective to you.

The best performance (and on some motherboards, your only choice) for high FSB overclocking, is high MHz ram.

in my system, i need 400MHz FSB to reach 3.6GHz - double that (For DDR ram) and thats 800MHz. i'm already at 800MHz, the max for that ram. since i have 1.1GHz ram, i can keep going all the way upto 550FSB (even tho my CPU Cant take it)

more or less, high MHz ram just takes ram out of the equation - its one less thing to worry about when OCing

 

[WarEagleAU]

Thanks Mussels, I didnt know that.

 

[theeldest]

The way that I understand it, many sticks are rated (completely tested and guaranteed to work) at a certain speed (let's say 1067MHz), but require a higher voltage than the standard. So the settings the memory has as default bring it to 800MHz so that it guarantees that the computer will boot properly, with the expectation that you will set it to the proper settings.

I've had corsair and G.Skill memory that both did this. They were rated higher, but at different voltages than standard, so they come up as 800MHz (or 400MHz if we go back further) and require the user to change the settings manually to the rated settings. The directions for both sets of memory actually said this. (as did the reps from both companies).

If they set the memory to tell the MB to run the memory at fast speeds, even if the memory can handle it at standard voltage, they run the risk of people putting it in motherboards that can't handle it, and won't boot properly. So they give standard settings to guarantee a good boot.


This is the way I understand it, and I would appreciate any input, I've only dealt with about half a dozen different sets of memory.

 

[Mussels]

The way that I understand it, many sticks are rated (completely tested and guaranteed to work) at a certain speed (let's say 1067MHz), but require a higher voltage than the standard. So the settings the memory has as default bring it to 800MHz so that it guarantees that the computer will boot properly, with the expectation that you will set it to the proper settings.

I've had corsair and G.Skill memory that both did this. They were rated higher, but at different voltages than standard, so they come up as 800MHz (or 400MHz if we go back further) and require the user to change the settings manually to the rated settings. The directions for both sets of memory actually said this. (as did the reps from both companies).

If they set the memory to tell the MB to run the memory at fast speeds, even if the memory can handle it at standard voltage, they run the risk of people putting it in motherboards that can't handle it, and won't boot properly. So they give standard settings to guarantee a good boot.


This is the way I understand it, and I would appreciate any input, I've only dealt with about half a dozen different sets of memory.

To simplify it even further: voltage cant be autodetected, so enthusiast RAM defaults to slower speeds and timings.

 

[theeldest]

let me put it into perspective to you.

The best performance (and on some motherboards, your only choice) for high FSB overclocking, is high MHz ram.

in my system, i need 400MHz FSB to reach 3.6GHz - double that (For DDR ram) and thats 800MHz. i'm already at 800MHz, the max for that ram. since i have 1.1GHz ram, i can keep going all the way upto 550FSB (even tho my CPU Cant take it)

more or less, high MHz ram just takes ram out of the equation - its one less thing to worry about when OCing

I don't think that's quite true. If I'm understanding you, once your memory hits your processor's FSB, you gain no benefit from OCing the memory.

I've done test where I can show this isn't true.

Here's my hypothesis:

Memory runs at a speed, let's say 800MHz. The clock ticks 800 million times per second. The clock with memory is a bit weird though. Because certain functions of memory take different amount of time (the timings of memory (5-5-5-15) are the number of clock cycles to wait while a function finishes).

Take the example of 5-5-5-15 memory. (I'm going to simplify, please bear with me). The first two numbers are how long it takes to find the memory address you're searching for. (row and column). So it takes 5 cycles to find the byte you want, then it takes time to read the byte.

Best case scenario, if your memory is at 800MHz (with a FSB of 400MHZ & DDR2), you're reading your memory at 20% the speed of your FSB. You could stick memory 5x faster in there before you wouldn't notice a speed increase.


In some cases, it'll do you more good to have quicker memory (and leave the CPU alone) whearas other time it'll be better to forget memory and speed up the CPU. To say that high Mem MHz removes Mem from the equation is like the old physicist trick of assuming a frictionless surface or assuming a spherical body (wait .... I'm a physicist ...).

Ok, so for beginning OCers, assuming that memory speed > FSB = no bottleneck will work fairly well. It's when you want that last 10% that it becomes more important to realize what's going on.


Disclaimer: I don't know dick about Intel, only AMD (and not so much the quad core). If this changes anything, please let me know?

 

[theeldest]

To simplify it even further: voltage cant be autodetected, so enthusiast RAM defaults to slower speeds and timings.

Mussels, you've a way with words that I can only dream about.