standard vs Ballistix memory

[pband]

Rob recommends Ballistix vs. standard Crucial memory. In the course of a discussion to determine what memory is appropriate for my motherboard, the Crucial on line representative and I had the following exchange:

Peter: So I probably would want four 1-GB Ballistix chips with the highest frequency, and lowest voltage for minimum power dissipation.
Doug : I would use the standard memory.
Doug : Are you needing Ballistix?
Peter: Why not Ballistix? Ballistix is faster than standard isn't it?
Doug : You need to change the voltage and timings in your BIOS.
Doug : They are not stable. Made for gamers.
Peter: Are you saying that to take advantage of the Ballistix chips one must reconfigure the bios settings? what is unstable? Are the Ballistix chips themselves unstable? Or the bios settings required result in an unstable system?
Doug : By changing the BIOS voltage and timings the system will not be as stable as standard memory.
Doug : Yes you need to change the BIOS to take advantage of Ballistix.

Nothing I have seen on the MySuperPc site or in my copy of the printed assembly tutorial mentions this. Or have I missed it? Does anyone know anything about this?

Thanks, Peter

[RickyTick]

Peter,

I told you to stay with the Standard memory. The Ballistix is for gamers and not stable. Listen to me.

Best regard,
Doug

[RickyTick]

OK, just kidding. I'm not really Doug. :D


The Ballistix memory does sometimes require a voltage change in the BIOS. Most motherboards default to 1.8 volts for the ram. Some ram requires 2.0 to 2.1 volts. Its really not a big deal, and very easy to fix.

You might try going to Crucials website and use their Ram Configurator to suggest the best ram for you.

Sorry for jerking your chain. I couldn't resist. :D

[RickyTick]

I hope I didn't make him mad. :confused:

[The Wise Monkey]

Haha, you may have done. xD

[pband]

Jerking the chain did put me off a bit. It influenced me to forget to thank you for responding. Thanks.

And since you seem willing, I have further questions.

Going to the Ballistix web site and using the Ram Configurator got me nowhere because I couldn't find my motherboard in the MB drop down list. It is the MSI (Micro Star) MS-7250 (K9N SLI Platinum). That's what got me to contact the Crucial help. It was only through 'Doug' the online guy that I got to the url:

http://www.crucial.com/store/listparts.aspx?model=ms-7250+(k9n+sli+platinum)

First I plan to upgrade to either four 1Gb or two 2Gb chips. Is there any advantage to one option vs the other?

Next, they list both 1.8 and 2.0 V chips as though it didn't matter. The regular chips seem to run at 1.8 V and the Ballistix at 2.0 V. How do I know if the MB will auto reset its supply voltage? If not, how do I know that I have to reset it? And how do I do it?

The chip descriptions include DDR2 PC2-5300, PC2-6400, PC2-8500. I believe the last part refers to speed (frequency). Is there any advantage to using the 8500 on my MB? (What are the units? 6400 MHz?) (Is there a decoder ring somewhere?)

I desire to get maximal speed out of what I have w/o overclocking. I'm not ready to try that yet.

Yes, I'm new to all this...

Thanks,
Peter

[RickyTick]

I found your motherboard on Crucial's configurator.
http://www.crucial.com/store/listparts.aspx?model=MS-7250%20Ver%202.0%20%28K9N%20SLI%29

If you're interested in 4gb of ram, its usually best to go with Two 2gb sticks as opposed to Four 1gb sticks. Fewer sticks tend to be less problematic, plus it offers a better upgrade path later on.

I got this off Crucials website.
http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=C4529D98A5CA7304

Changing the ram volts is a simple change in the BIOS.

[The Wise Monkey]

From the MSI website for your motherboard (http://www.msicomputer.com/product/p_spec.asp?model=K9N_Platinum):

Main Memory

•
Supports dual channel DDR2 533/667/800, using four 240-pin DDR2 DIMMs.
• Supports the memory size up to 8GB
• Supports 1.8v DDR2 SDRAM DIMM
Due to the High Performance Memory design, motherboards or system configurations may or may not operate smoothly at the JEDEC (Joint Electron Device Engineering Council) standard settings (BIOS Default on the motherboard) such as DDR2 voltage, memory speeds and memory timing. Please confirm and adjust your memory setting in the BIOS accordingly for better system stability.
Example: Kingston HyperX DDR2-800 PC-6400 operates at 2.0V, 4-4-4-12.
For more information about specification of high performance memory modules, please check with your Memory Manufactures for more details.

What this means is that you will need to change the memory voltage and timings in the BIOS to match those of the RAM you buy in order to get the most stability.

[pband]

Gents:

Thanks for the reply. But what is the meaning of:

533/667/800 ?

4-4-4-12 ?

DDR2 PC2-5300, PC2-6400, PC2-8500 ?

Thanks.

Peter

[The Wise Monkey]

To explain this, let's break down what I said: "Kingston HyperX DDR2-800 PC-6400 operates at 2.0V, 4-4-4-12"

1. Kingston HyperX: The brand/make of the RAM. Kingston is a well known brand, but we recommend more high performance brands such as Corsair and Crucial.

2. DDR2: This stands for "Double Data Rate 2". This is quite difficult to explain, but imagine your RAM as a clock that only has the numbers 12 o'clock and 6 o'clock. Older RAM could only read and write data when it came to 12 o'clock, but DDR2 can read and write at 12 o'clock and 6 o'clock, thus giving double the data rate, hence the name. In reality it is more complex than this, but this is the general gist of it.

3. 800:This is the equivalent of clock speeds in a CPU, but in MHz. So your CPU might have a frequency of 2.2GHz and your RAM would have a frequency of 800MHz. Using the clock metaphor before, this is the number of times that the hour hand rotates per second. So 800MHz means that the hour hand spins 800,000 times in one second, going past 12 o'clock and 6 o'clock each time. As such, the higher the frequency the better, as more data can be transferred to and from the RAM.

4. PC2-6400: The number here represents the peak data transfer rate to and from the RAM, in MB/s. So 6400 means a peak transfer rate of 6400 MB/s, or 6.4GB/s. Similarly, PC2-5300 means a peak transfer rate of 5300 MB/s, and so on.

5. 2.0V: This is the required voltage needed in order for the RAM to run stably at the correct specifications. Most BIOSs default to something lower than this in order to accommodate every stick of RAM available, so you will usually need to change it to match your RAM.

6. 4-4-4-12:Each number stands for something different, but the most important one is the first number, as this represents the CAS latency of the RAM. CAS stands for Column Address Strobe, but you don't really need to know about the technical details. All you need to know is that the CAS latency is the delay time (in number of clock cycles) between a piece of data being requested from the RAM and when it is outputted. Again, with our clock metaphor (handy, isn't it?), this is the number of times the hour hand spins around after the data is requested and before it is returned. From this, the lower the CAS latency, the better.

I hope this makes sense. :)

[pband]

Thanks for enlightening me.

In response item 3 you say 'spins 800,000 times in one second'. If I follow you, I think you meant 'spins 800,000,000'.

Combining response items 3 and 4 implies the chip description may have some redundancy, for those who understand. Assuming I understand. The 800 frequency spec, 800Mhz, assuming one byte is transferred with every cycle and with 8 bits per byte, implies 6,400 M-bits/sec. Correct? But, the double data rate suggests 2 bytes per cycle which would be 12,800 M-bits/sec. What am I missing?

Is the 4-4-4-12 spec something that is characteristic to the motherboard and the chip must be chosen to match or is it something that is characteristic of the chip and the motherboard can be adjusted to match?

If I get the Ballistix memory, which requires 2.0V, whereas my motherboard apparently defaults to 1.8V, I assume there is no chance of damaging anything. But, will the machine start up adequately to be able to work in the bios to adjust the voltage? Or does the bios not use RAM? And how to I adjust the voltage via the bios? Where can I find instructions?

Cheers, Peter

[The Wise Monkey]

I've managed to confuse myself - the 800 part refers to the number of millions of transfers per second, not the clock speed. The actual clock speed of some DDR2-800 RAM is 200MHz.

The 4-4-4-12 spec represent the optimal manufacturer's recommended timings for the RAM, but the RAM can be forced to run faster or slower if need be. You make the adjustments in the BIOS to match those recommended for your RAM. The BIOS itself doesn't need any RAM to display, so there is no harm in booting into it first to change the voltage and timings.

The location of the settings varies between BIOSs, so just have a look around yours and see what you can find - this is the best way to learn. :D

If you are interested in the specifics of RAM, check out the wikipedia article:

http://en.wikipedia.org/wiki/DDR2_SDRAM