Simple RAM Timings and OC Questions

[Garet Jax]

It has been a long time since I have OC'd anything and am not really interested in doing so now, but I want to make sure my buying decisions work together.

Last time I OC'd, the chip speed was determined by an internal multiplier and the FSB. If you bought RAM that couldn't run at the pre-set FSB in the BIOS for the chip, then slowing down the FSB would also force the chip to slow down unless you adjusted the multiplier. If the multiplier was locked then you were out of luck - unless you could unlock it. Does any of this still apply for AMD AM3 chips? Does it depend on the particular AM3 chip?

I definitely did not get much into RAM timings and know very little about it.

In the market for an AM3 chip and board. Still deciding between the Athlon II and the Phenom II.

I am thinking of buying DDR3 RAM that is clocked at 1333 (PC3 10666) with published timings 9-9-9-20 and wondered if this will limit my chip or board decision.

Thanks in advance.

 

[Garet Jax]

No one has anything to say...

 

[Bartman39]

Dont know about AMD but figure its pretty close as with FSB and ram speeds and I found 1333 DDR3 is just not enough for the good OC`s... Its better to get higher rated ram and run it at less mhz with tighter timings and lower voltage... JMPO...

 

[Garet Jax]

Dont know about AMD but figure its pretty close as with FSB and ram speeds and I found 1333 DDR3 is just not enough for the good OC`s... Its better to get higher rated ram and run it at less mhz with tighter timings and lower voltage... JMPO...

Thanks for the post. I really have no intention to OC anything. I simply want to get the machine up and running with stability. On the same note, I don't want the hardware to drastically under perform.

If I set the RAM speed to 1333 is that going to force the chip to POST at a lower gigahertz that what it is rated?

What speed generally are the AMD AM3 chips rated and are they locked?

 

[Ben90]

Dont know about AMD but figure its pretty close as with FSB and ram speeds and I found 1333 DDR3 is just not enough for the good OC`s... Its better to get higher rated ram and run it at less mhz with tighter timings and lower voltage... JMPO...

1333 is definitely enough for a ridiculous Intel OC. You might notice a thing in your BIOS called a memory multiplier. You can get a 930 up to 4.9Ghz without even overclocking your DDR-1333 RAM.

*edit*

And to the OP, I see no reason not to get DDR-1333. As far as I know, no AM3 processor supports anything higher than that. Even if it did, the gains won't be notifiable as modern processors have fat caches and RAM performance isn't as big of a deal as it used to be.

 

[Garet Jax]

1333 is definitely enough for a ridiculous Intel OC. You might notice a thing in your BIOS called a memory multiplier. You can get a 930 up to 4.9Ghz without even overclocking your DDR-1333 RAM.

*edit*

And to the OP, I see no reason not to get DDR-1333. As far as I know, no AM3 processor supports anything higher than that. Even if it did, the gains won't be notifiable as modern processors have fat caches and RAM performance isn't as big of a deal as it used to be.

Thanks - I struggled a lot with the buying decision on the memory. I am looking at 2 X 4GB and the price difference between 1333 and 1600 is about $100. $100 covers the MB or the OEM OS or most of the chip or 2.5 extra HDs or the case (you get the idea). It is a lot of money to consider.

 

[richierich1212]

AMD systems love tighter timings more than anything, so try to get 1333 7-7-7-1T at the minimum.

 

[Garet Jax]

AMD systems love tighter timings more than anything, so try to get 1333 7-7-7-1T at the minimum.

OK - Given the choice between 8GB RAM at 9-9-9-20 or 4GB RAM at 7-7-7-20. Which would you choose for the better performance?

Unfortunately, the price difference is sufficient to push me beyond my budget at 8GB with the lower timings.

 

[betasub]

OK - Given the choice between 8GB RAM at 9-9-9-20 or 4GB RAM at 7-7-7-20. Which would you choose for the better performance?

The gain from tighter timings is minimal in almost all cases. Then again, the gain from having 8GB of RAM over 4GB is minimal if your usage profile never approaches 4GB.

Benchmarking or apps that rely on memory latency should give the win to tighter timings. Apps that edit huge files (video etc), or run concurrently with large memory footprints should favour the extra RAM.

The average user would be fine with "only" 4GB at 9-9-9-20.