Which DDR3 kit for ASUS P5E3 X48 and Q9450?

[ichi1]

Hi,

I am trying to find the right RAM to go with the ASUS P5E3 X48 and Q9450. The computer will be used for gaming, photo editing (5D RAW, CS2, DPP), video editing (Premier Elem.) and work (VC++ 2008 -- very large project). These are the modules that I have in mind:

G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) -- 7-7-7-18 -- $419.99
OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) -- 7-6-6-24 -- $420.99 <-- What I am thinking would be the best...
OCZ Reaper HPC 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) OCZ3RPR13334GK -- 6-6-6-18 -- $310.99 (with heat pipes -- will I be able to fit four of them in the P5E3?)
OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) OCZ3P13334GK -- $249.99 AR -- 7-7-7-20

The main question I have is what RAM will be best paired with an overclocked Q9450? The SILVERSTONE NT06-LITE CPU Cooler will be riding on the CPU.

Any suggestions are welcome!

Cheers!
- ichi1

 

[DSF]

Is there a reason you're set on DDR3? DDR2 is far less expensive with essentially no performance loss.

 

[ichi1]

Well, I got the feeling, from reading various reviews, that X48 and Q9450 come alive with high performance DDR3. It seems that that is when X48 outshines X38 and P35. But I might be wrong about that.
The future is definitely DDR3, so buy I thought it would be a good idea to buy 4GB of DDR3 now and another 4GB once prices have come down (in a year?).
Also I thought running DDR3 1600 would be a good match if I can overclock the Q9450 to use a 1600MHz FSB. Does this make sense?

Thanks
- ichi1

 

[DSF]

When Intel reports the FSB of a processor, they inflate the number. Intel processors quad-pump the frontside bus, which means they make four transfers per clock cycle. The actual operating frequency of the frontside bus for a Q9450 @ 1600 is only 400MHz. DDR (including DDR, DDR2 and DDR3) makes two transfers per clock cycle. So there are 800 transfers per second for DDR running on a 400MHz frontside bus. That's where the 800 in DDR2-800 comes from.

Since modern RAM is usually run in a dual-channel configuration, you have 800 transfers per clock to each of two sticks of RAM. So 800 per stick becomes 1600 total transfers per second between the CPU and RAM. To sum all of that up, the RAM speed that matches a 1600FSB processor is actually DDR2-800, not DDR3-1600.

I'd be interested to see those reviews where they found significant gains from DDR3. I think you'll find you're spending an excessive amount of money between the X48 board and DDR3 that is giving you almost no real-world performance improvement over a simple P35/DDR2 setup.

Then again, maybe X48 handles DDR3 much better than P35 and X38 have. Like I said, I'm interested to see the reviews.

 

[secretanchitman]

the one you picked..the first ocz under the g.skill out of those 4.

unfortunately and sadly, those prices are only going to go down day by day...

 

[ichi1]

Originally posted by: DSFSince modern RAM is usually run in a dual-channel configuration, you have 800 transfers per clock to each of two sticks of RAM. So 800 per stick becomes 1600 total transfers per second between the CPU and RAM. To sum all of that up, the RAM speed that matches a 1600FSB processor is actually DDR2-800, not DDR3-1600.

I'd be interested to see those reviews where they found significant gains from DDR3. I think you'll find you're spending an excessive amount of money between the X48 board and DDR3 that is giving you almost no real-world performance improvement over a simple P35/DDR2 setup.

Then again, maybe X48 handles DDR3 much better than P35 and X38 have. Like I said, I'm interested to see the reviews.

Thanks for the explanation of frequency vs. data rates. I sort-of knew that, but I thought there might be an advantage to having an even divisor between FSB and RAM speed.

Here's a reviewer talking about how X48 may be better than older chipsets when it comes to high performance From: AnandTech's P5E3 X48 review (p.5):

It's hard to argue with the performance potential this system brings at these settings, something that current X38 users might find impossible when aiming for total stability. Perhaps the most impressive point in this accomplishment is that our MCH required only 1.35V in order to run hour after hour of Prime95 or other stress tests without error. There are those that may believe this is not much to speak of, but the combination of high CPU speed and low tRD is brutal on the MCH - something we plan to explore soon in great detail. In fact, this is exactly where the X48 chipset begins to shine - in some of the situations where the X38 would either fall flat on its face or require voltages well in excess of those we feel comfortable using on a daily basis.

I am not married to DDR3. Money is not the number one concern, but I don't want to be wasteful either. What DDR2 mb and RAM do you think would approximately match the ASUS P5E3 Premium WiFi X48 board with DDR3 1600 RAM?

I need dual RAID0 arrays.

Cheers
- ichi1

 

[ichi1]

Originally posted by: secretanchitman
the one you picked..the first ocz under the g.skill out of those 4.

unfortunately and sadly, those prices are only going to go down day by day...

Yeah, well, I have waited long enough... Now is the time to build

Thanks for your input.
- ichi1