DDR3-1333 CL7 or DDR3-1600 CL8

[Rhezuss]

I'm a memory newb and i'm currently looking to buy some parts.

The thing I know is that the RAM freq being important, the timings play a greater role in speed...so after looking a bit at the market, I have a question about 2 types of RAM:

What would be the better RAM between 8gb of DDR3-1333 CL7 and 8gb DDR3-1600 CL8?

The 1333 CL7 being relatively cheaper (~$15-$20 less than the 1600) I wonder what diff a system would see with those 2...

Thanks!

 

[Ratman6161]

I'm a memory newb and i'm currently looking to buy some parts.

The thing I know is that the RAM freq being important, the timings play a greater role in speed...so after looking a bit at the market, I have a question about 2 types of RAM:

What would be the better RAM between 8gb of DDR3-1333 CL7 and 8gb DDR3-1600 CL8?

The 1333 CL7 being relatively cheaper (~$15-$20 less than the 1600) I wonder what diff a system would see with those 2...

Thanks!

This article should answer your question: http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3

Its talking about SandyBridge platforms but even if you have something older the information probably still holds true. Basically the conclusion is that clock speed counts for more than latency so in the two you compare, the 1600 CL8 would be faster than 1333 CL7. Then again it also concludes that there is very very little difference between the fastest and the slowest.

Another option you should consider is plain old 1600 CL9 which will be cheaper than either of the options you list - and like I said performance wise it makes very little difference.

 

[Rhezuss]

Thanks for the article link, very informative.
Might as well stick with 1600MHz.

Thanks again

 

[mmaestro]

Worth checking, before you spring, what processor you're pairing this with? While once you hit 1333 CL8 or 1600 CL9 for Sandy Bridge, anything more is really a case of diminishing returns, that's not the case for other platforms. For instance, a Llano APU really benefits from faster memory and natively supports DDR3-1866 to boot. IIRC earlier Intel platforms also benefited more from faster memory, it's really the Sandy Bridge architecture that makes faster memory less relevant.

 

[Rhezuss]

Worth checking, before you spring, what processor you're pairing this with? While once you hit 1333 CL8 or 1600 CL9 for Sandy Bridge, anything more is really a case of diminishing returns, that's not the case for other platforms. For instance, a Llano APU really benefits from faster memory and natively supports DDR3-1866 to boot. IIRC earlier Intel platforms also benefited more from faster memory, it's really the Sandy Bridge architecture that makes faster memory less relevant.

Well for now it'd be coupled with a Phenom II X4 955 @ 3.6GHz. Not the bomb SB is I know. But, in the near future it'll work with a BD CPU, which one, I don't know.

That's why i'm looking at AM3+ mobos now and DDR3. My current setup is limited to DDR2 and AM3.

Memory is confusing when you look at it. But thanks for you guys it's a little clearer now.

While shopping I saw memory "Designed for Intel P67 motherboards" in their descriptions, like this one http://www.newegg.ca/Product/Product...82E16820231428

Is there gonna be equivalent memory "Designed for AMD motherboards"?!?

 

[Blain]

I'm a memory newb and i'm currently looking to buy some parts.

The thing I know is that the RAM freq being important, the timings play a greater role in speed...so after looking a bit at the market, I have a question about 2 types of RAM:

What would be the better RAM between 8gb of DDR3-1333 CL7 and 8gb DDR3-1600 CL8?

Rated voltage for the two is a specification you left out of the picture.
Got any information on that?

 

[Ratman6161]

Rated voltage for the two is a specification you left out of the picture.
Got any information on that?

The voltage spec for DDR3 memory is 1.5V. Personally I would not touch any memory that's looking for greater than that. It seems to me that memory calling for greater than spec voltage are just overclocked out of the box. So if they are claiming high speeds or low latency then you have to wonder if they are just cranking up the voltage to get those speeds rather than actually using memory that is any faster.

Also if you are considering SandyBridge then you defintely do not want anything that requires higher than standard voltages. Besides, there are plenty of good choices out there that don't need above spec voltages.

 

[Blain]

I'm a memory newb and i'm currently looking to buy some parts.

The thing I know is that the RAM freq being important, the timings play a greater role in speed...so after looking a bit at the market, I have a question about 2 types of RAM:

What would be the better RAM between 8gb of DDR3-1333 CL7 and 8gb DDR3-1600 CL8?

Are there differences in the voltage ratings for each kit or are they both rated at 1.5v?

 

[Rhezuss]

Are there differences in the voltage ratings for each kit or are they both rated at 1.5v?

Both are 1.5v

And whats that about rated 1600 RAM showing 1333 in the BIOS and the user have to OC it's RAM to the marketed speed!??

 

[EarthwormJim]

Actually the latency (in nano-seconds) is slightly lower on that CL8 ram than the CL7.

(1/800mhz)*8 = 10 ns

(1/667mhz)*7= 10.5 ns


Keep in mind those ratings are listed in clock cycles. So even though it might take more clock cycles for CL8, each clock cycle occurs in less time.

With the DDR3-1600 RAM you have basically identical timing latencies as the 1333 RAM, and the benefit of higher transfer rates.

 

[Blain]

I wonder what diff a system would see with those 2...

none