1:1 fsb:dram ratio -- real or myth?

[Deja Q]

If it's a 1:1 ratio, will there be tangible performance improvements, even if this mean the RAM's timing must be halved?

(my CPU FSB is 333mhz; my RAM is stated toi run at 800MHz - the mobo sees it as 1000mhz but I can underclock it to 667mhz, with faster CAS and other timings.)

[Gore1FL]

1. My understanding...

is that the ram speed gets doubled relative to the FSB. Hence a "real" 400 Mhz makes for an actual 800 Mhz, likewise with a 333 to 667.

I would think setting it to run at 667 with faster settings will give you more bang for the buck. The easiest thing to do would be to test it with a freeware benchmark tool.

[Deja Q]

2. I tried that.

Yup. Difference. :7

The CPU remained at 32 C, much to my amazement. (The zalman 9700 rox!)

UT2004, for 15 minutes, went from 80fps (worst) to 315fps (best). I've never seen 300 fps before on the same system...

I'll try one of the more intricate maps later; one that will reduce the system to 25fps under full load (max monsters).

And Bryce rendering - that'll bloody scream!!

Some say the 1:1 thing is a myth; max bandiwdth being more important.

Usage with Vista contradicts this; the system starts faster with the tightened timings, sidebar and all... bandwidth may only be 51000 instead of 59000, but it's used more effectively. That much is clear.

I *might* try 3.6GHz CPU (9x400mhz) so I can use the RAM at its intended 800mhz (it's able to do 4-4-4-12 @ 2.1v @ 800mhz; right now it's doing 4-4-4-12 @ 2.0v @ 667MHz) but I suspect the CPU would get too hot. So I'll try the RAM at 3-3-3-8 @ 2.0v @ 667MHz instead. :9

[Gore1FL]

3. I am a big FSB and L2 cache fan

I figure with a core 2 duo with a lot of l2 cache and a screaming FSB, you gain more than with a faster internal multiplier. The processor doesn't seem to be the constraint unless you are really doing some outrageous crunching.

In the early P4 days, a friend bought a 400Mhz FSB PC with minimal L2 cache when I bought an 800FSB PC. Hers is rated at the same speed as my older desktop--2.4Ghz, but I can start and restart mine 2.5 times in the time that it takes hers to come up once.

I bought a dell laptop from their outlet store (2.0Ghz with a core 2 duo 7300 (4 MB L2 cache). The FSB is 800Mhz, but it shipped with 667 memory. I can bring it up, restart it (in 32 bit vista vs the Desktop's XP) in the the time it takes to load the Desktop. The second core ( and the fact that both are faster) has a lot to do with this, but I have to think the L2 cache plays the biggest role in that case--and of course boot up is a little more processor intensive)

If you look at new processors, you might seriously consider going with an 8MB L2 cache, and jumping up to the fastest FSB (1333?). That is if money isn't an object...

[Deja Q]

4. It's an object...

:)

The Q6600 has two 4MB L2 cache modules... Core 266MHz FSB, but can be o/c'ed to 333 easily and many have made it to 400... not sure about going higher than that...

[Gore1FL]

5. I quit overclocking at the P IIl level

after I discovered burn marks on my slot 2 card!

You might consider getting a peltier and some big-assed fans.

[MyNameGoesHere]

6. peltiers! NOOOO!

Asking for heart ache, condensation is a bitch. A closed water cooler is a much better solution nowadays.

[Gore1FL]

7. Fair enough

last time I used a peltier was in 2001.