Just purchased new RAM - I've got a question

I just purchased two sticks of 1GB 667MHz Corsair Value-Select RAM for my VAIO SZ. When I opened CPU-Z and clicked on the "Memory" tab I found the frequency to be 266.7 MHz. Shouldn't it be 667 MHz? I also clicked on the SPD tab and noticed that near Max Bandwidth it said "PC5300 (333 MHz)." Shouldn't that say 667 MHz? Is there something I haven't done? Thanks!

 

As has been pointed out here many times, the SZ motherboard supports a maximum RAM speed of 533MHz. If one uses RAM that is any faster than this the system simply slows it down to 533MHz.

Now [I will go slowly here ] considering that [1] the SZ maxes out memory speed at 533MHz and [2] the SZ utilizes a dual channel memory architecture – 266MHz multiplied by 2 equals - what?

Yup, 533MHz.

Cheers.

 

DDR2 can do two operations in one cycle. So, the memory is actually running at 266. Since it can do two operations, it is labeled as 533 (266*2). I still cannot figure out why Sony used a 667 FSB and limited to memory speed to 533. It is confusing. Have been using 2GB 667 memory for months now with no problems.

 

I knew the SZ maxed out at 533MHz (I purchased the 667MHz because it was only 10 dollars extra and because I've read rumors that "if" Sony releases a new BIOS to accommodate 64-bit computing that they may also increase the max memory speed from 533MHz to 667MHz), but what I didn't know (until now) is that the frequency is divided between the two channels. Thanks for the help!

 

I am about to purchase extra RAM to upgrade my SZ240 as well. Does it seem reasonable to buy the 667MHz instead of the 533MHz seeing as it only costs 4 dollars more on newegg? Or is it a waste because there is no hope of Sony releasing a new BIOS? Will the 667 run the same as the 533 if Sony never wises up?

667MHz:
http://www.newegg.com/Product/CustRatingReview.asp?Item=N82E16820145012

533MHz:
http://www.newegg.com/Product/Product.asp?Item=N82E16820145593

 

I have the same question - I have 2 sets of RAM - 1 2 x 1GB Corsair 667 Mhz DDR2 and 1 2 x OZC 533 Mhz.

I wonder which to put into my sz120p - will the faster ram actually be slower because it has to be clocked down?

 

Really doesn't matter.

The cost difference is now so little that if you think you might upgrade to a laptop that supports 667 RAM in the near future then go for it but as regards the SZ there will be no difference [unless you plan on manually overclocking your RAM and RAM/FSB settings using some 3rd party app].

As for 533 running at 533 vs. 667 clocked down to 533 there will be no difference in performance.

 

thanks very much!

 

Yeah, thanks.

 

Hi zswan. Your understanding of DDR memory frequency is absolutely false, fueled by people who don't know what they're talking about. The post, directly above yours, by dhill is the correct reasoning.

533 Mhz DDR is in fact running at 266mhz speed. However, compared to SDR (i.e. SD RAM), it can do 2 times as much work at the same speed. That is where the 533 comes from. Even if you have only 1 stick of DDR ram, it will still be running at 533 (2 x 266).

Dual Channel is about memory bandwidth, which is different (but related) to memory frequency. Put simply, the higher the memory frequency, the more theoretical memory bandwidth available per channel (this is the benefit of higher frequency in the first place i.e. 667 v 533). Dual channel doubles the theoretical memory bandwidth available to the proccessor.

Higher memory frequency and memory bandiwdth DOES NOT neccessarily result in faster performance. This is because higher frequency memory often comes at the expense of the speed that memory can be accessed or memory timings. These are often quoted as 4 numbers (e.g. 3-4-4-8). The lower these are the better. For example, in the current situation the 533Mhz memory runs at tighter timings than the 667 memory (4-4-4-8 v 5-5-5-15).

Thus the 667 Mhz will not really improve system performance much, if at all. In fact, for office applications and general tasks the 533 memory with its tighter timings will probably perform better than the 667Mhz memory. This may be the opposite for games and graphics/video editing software.

For more info, read this article and ignore the reference to what is currently avilable. What is important is the talk about memory timings and memory frequency.

Weshy.

 

Last post is on the mark. DDR2-533 is a better bet than DDR2-667 for laptops at this time. DDR2-533 is usually CL4. DDR2-667 is usually CL5. That timing difference pretty much negates any performance advantage. Run the benchmarks on a laptop which can take both and you will see no difference (or virtually none)

The DDR2-667 memory might run hotter too, so it could even be a negative.