Performance memory: only for overclocking?

[slowpogo]

Hello. I'm building an AMD system, and while I was just going to grab 2 gigs of value ram and be done with it, I'm starting to wonder if I should spend the extra $ on performance memory, such as Corsair XMS.

While I have overclocked my processor before, I know nothing about overclocking memory and if I try it, I will be cautious and probably only marginally successful at it, and I'm fine with that.

Does performance memory give a significant performance boost at stock speeds? I will be gaming (Oblivion, COD2) and using Dreamweaver, Photoshop and Cubase a lot, if that helps. Thanks!

 

[chusteczka]

performance memory is useful to prevent the need of lower memory dividers when overclocking.

For instance, with standard memory, it takes a 5:6 memory divider to bring the cpu up to 250MHz since standard memory typically can only go up to 225 or 230MHz without settting a memory divider. Meaning the memory is running at the same speed as the cpu, 1 clock cycle for 1 clock cycle. Since the memory possesses a maximum of 225MHz but the cpu can go much higher than that, a memory divider is required to allow the cpu speed to go faster than the memory speed. Typically 166MHz memory to 200MHz cpu. (166/200 or 5/6) This is 5 memory clock cycles for 6 cpu clock cycles.

The 5/6 memory divider slows down performance by about 7%. The way to get around this is to purchase premium memory that can be stable at a higher speed. The best premium memory for AMD socket 939 would be the PC4000 (500MHz). This allows the memory to run at 250MHz without requiring a memory divider, thus allowing the cpu to run at 250MHz without experiencing that 7% performance loss.

However, the cpu's with the larger multipliers (say 12, 13, or 14) do not need to run so high as 250MHz per the following calculations:
289MHz * 9 = 2601MHz
260MHz * 10 = 2600MHz
237MHz * 11 = 2607MHz
217MHz * 12 = 2604MHz
200MHz * 13 = 2600MHz
200MHz * 14 = 2800MHz

For a cpu with a larger multiplier (12, 13, 14), it can be seen that standard memory will work just fine to achieve the higher system speeds.
For a cpu with a smaller multiplier (9, 10, 11), it can be seen that performance memory will help to allow a higher overclock with less performance loss due to a memory divider.

 

[pkme2]

According to the previous threads on AT, OCZ Platinum seems AOK for performance seekers.

 

[PhoenixOrion]

what kind/speed of AMD processor do you plan to overclock?

 

[slowpogo]

X2 3800+ at the moment...but still debating whether to go with 939 or AM2.

I am a total novice at overclocking, but I'm told if you're not out to break any records and just want a modest performance boost, it's not too difficult.

 

[chusteczka]

Originally posted by: slowpogo
X2 3800+ at the moment...but still debating whether to go with 939 or AM2.

I am a total novice at overclocking, but I'm told if you're not out to break any records and just want a modest performance boost, it's not too difficult.

Unless you are en enthusiast, which it does not seem you are, it would be more logical to purchase a well developed, mature, yet still new technology like a socket 939 system. If you are planning to purchase something now, rather than wait, the current AM2 motherboards will contain bugs that will take a few months to work out. These bugs could provide much trouble you may have difficulty working around. Read through my thoughts on socket 939 in this thread

The original question concerning RAM and CPU comes down to a situation where you could purchase a mid-level cpu with mid-level RAM. To obtain better performance, you could purchase:

• better cpu with value ram
• mid-level cpu with premium RAM certified at a higher speed
• better cpu with premium RAM

Just be careful you do not purchase a high performing cpu with a large multiplier (12 or higher) with premium RAM. That would be a waste of money. The 3800+ X2 s939 with premium PC4000 (500) RAM would be a perfect combination for overclocking but a waste of money on the RAM if you will not overclock.

 

[slowpogo]

I'm becoming an enthusiast 🙂 I'll wait for the first round of nforce 500 reviews. If someone manages to make a solid stable board straight out the gate, I'll go for it.

Besides, aren't the bugs you speak of things that will go away with BIOS updates, mostly? I find it hard to believe that companies would release boards that can't run a simple system with standard ram, hd, graphics card. I'm sure more advanced tweaking might bring out some bugs..but I can wait on that stuff.

Though I'm probably totally wrong 🙂 let me have it...

 

[chusteczka]

You are correct.

 

[biostud]

it's not worth it IMHO, unless you can get it for a few extra $$$. You won't notice speed differences with a high memory speed compaired to normal. Use the money on a better videocard or save them.