Don't waste money buying 1600mhz DDR3!

[maxawesome]

I stumbled upon this today whilst reading other info pertaining to RAM (troubleshooting some errors I have in my RAM set):

http://www.intel.com/support/processors ... 029913.htm

For i7-900 series:

What is the maximum frequency for DDR3 memory when used with Intel® Core™ i7-900 processor series?
These processors support DDR3 memory with a maximum frequency of 1066 MHz. If faster DDR3 memory is used (such as 1333 MHz or 1600 MHz), it will be down-clocked to operate at 1066 MHz.

For i5/i7 800, 700, or 600 series:

What is the maximum frequency for DDR3 memory when used with the Intel® Core™ i7-800 processor series, the Intel® Core™ i5-700 processor series, and the Intel® Core™ i5-600 processor series?
These processors support DDR3 memory with a maximum frequency of 1333 MHz. If faster DDR3 memory is used (such as 1600 MHz or higher), it will be down-clocked to operate at 1333 MHz.

So basically, if you have an i7-900 series, you are best served buying 1066mhz RAM with the lowest timings possible (7-7-7-21 I think?), and if you have an i5/i7 800, 700, or 600 series, you should buy no more than 1333mhz with 7-7-7-21 for best performance.

What I initially read about DDR3 was that lower timings generally produce superior performance, which is why I bought 1333mhz/7-7-7-21 RAM when I built my CustoMac, but this just further bolsters that position.

 

[vindoan]

Motherboard manufacturer has BIOS that allows you to run faster memory than what Intel specifies. The CL timing has minimal affect compared to the speed you set your memory to run at.

Buying faster memory, and setting the correct BIOS settings to increase the clock speed of the memory, will improve performance more than memory running at a lower clock speed (but with faster CL timing).

Actually, when memory is rated at 1600MHz, it's actually running at 800MHz. DDR doubles the data rate each clock cycle. The 1600MHz is a marketing number.

Anyways, here's my memory running at DDR 1600 MHz (800MHz x DDR) with a Core i7 980X. I set the multiplier in the BIOS so that the memory runs at 1600. No down clocking observed:

 

[dh22r]

yes, but ...

what's the marginal cost/benefit btw getting 1066/1333 CL7's versus 1600 CL9's? aren't CL7's typical more $$$ than CL9's even for lower speeds?

also, the delta btw the "best" and "next best" can be quite small and performance-wise, insignificant.

just my 2 cents. :?

 

[Lnx2Mac]

Don't waste time reading BS FAQ

Note though that some RAM vendors OverVoltage their RAM to get it to run at spec'ed frequencies...
That's why I like my Eco's

 

[wavesequence]

Don't waste time reading BS FAQ

Note though that some RAM vendors OverVoltage their RAM to get it to run at spec'ed frequencies...
That's why I like my Eco's

Please elaborate a little more your thought...
I'd like to know if it's worth buying DDR3 1600MHz RAM or not.

 

[MacMan]

Don't waste time reading BS FAQ

Note though that some RAM vendors OverVoltage their RAM to get it to run at spec'ed frequencies...
That's why I like my Eco's

Please elaborate a little more your thought...
I'd like to know if it's worth buying DDR3 1600MHz RAM or not.

Yes, you will get better performance.

 

[humph]

As per the Tom'sHardwareGuide article, get the best priced "decent" brand memory with decent latency. In past couple of months, 1600MHz is more or less same (or even cheaper) price than 1300MHz - I guess that depends on where you live/buy from.
But if you find nice and well cheap 1300, then that's fine also. The difference in real world apps is probably less than 5% (THG). But do note to use 1600MHz at it's full speed, you may need to do a small overclock.
eg: standard BCLK and multi on my kit yields 1300MHz memory speed. I got 1300 memory (since 1600 more expensive at the time) and was able to o/c to 1600 anyway.

 

[wavesequence]

As per the Tom'sHardwareGuide article, get the best priced "decent" brand memory with decent latency. In past couple of months, 1600MHz is more or less same (or even cheaper) price than 1300MHz - I guess that depends on where you live/buy from.
But if you find nice and well cheap 1300, then that's fine also. The difference in real world apps is probably less than 5% (THG). But do note to use 1600MHz at it's full speed, you may need to do a small overclock.
eg: standard BCLK and multi on my kit yields 1300MHz memory speed. I got 1300 memory (since 1600 more expensive at the time) and was able to o/c to 1600 anyway.

Does this mean that I can buy 1600MHz memory if I plan to o/c?
And if I don't plan to o/c is 1300MHz RAM enough, or will I encounter a bottleneck?

 

[Lnx2Mac]

Don't waste time reading BS FAQ

Note though that some RAM vendors OverVoltage their RAM to get it to run at spec'ed frequencies...
That's why I like my Eco's

Please elaborate a little more your thought...
I'd like to know if it's worth buying DDR3 1600MHz RAM or not.

Definitely. The faster the merrier...

Does this mean that I can buy 1600MHz memory if I plan to o/c?
And if I don't plan to o/c is 1300MHz RAM enough, or will I encounter a bottleneck?

1600 has nothing to do with overclocking...
I have 2 non-overclocked systems with 1600, an i7-860 and an i5-750...

However, there's a correlation between your CPU speed and RAM speed, as these are set from a base-clock and 2 multipliers.

You might have to "fiddle" with the Base-Clock/Multipliers to find the right relation for these.
Sometimes, the numbers are identical to spec, and sometimes are 'close' (so it might mean a very slight over/underclock).
If you get XMP RAM, it will take care of finding "the golden ratios".

So, to summarize:
- Yes, you can go with 1600, and if you don't want to deal with clocks and multipliers, get XMP RAM.
- In RAM Voltage, less is more... Pick the vendor/model which claim to sustain a specific rate at the lowest voltage. For me that's been G.Skill Eco.

Good Luck,
Lnx2Mac

 

[wavesequence]

Good Luck,
Lnx2Mac

Thanks, I need your wishes