RAM Speed

[Herr-Berbunch]

Hi folks, I've currently got 4 Gb of Kingston ValueRAM DDR2-800 (PC-6400), I've been donated 4 Gb of Kingston HyperX RAM rated at 750 (PC-6000). My question is would the HyperX RAM have the edge over the value RAM despite the slightly slower speed?

Kingston appear to be the only guys who did RAM this speed, and the only things I can find are from it's initial release stating it's super-duper fast - but that was a few years ago and all RAM on it's inital release is called super-duper fast!

If nobody knows, is there a benchmarking suite (free) that'll give me in cold hard figures the result I'm looking for? :hmmm:

Thanks in advance.

Edit: Due to my wonderful (irony instead of asterisks!) mobo, I can't go above 2 x 2 Gb DDR2-800.

[Gerald]

You mean for overclocking, the Mhz? Look here,

http://www.techpowerup.com/gpuz/

[Herr-Berbunch]

You mean for overclocking, the Mhz? Look here,

http://www.techpowerup.com/gpuz/

No, not for o/clocking. The HyperX ram has a rating of 750, the value 800, but in real terms would the HyperX be better than the value - as we know, higher ratings of things don't necessarily mean the results are better.

[Gerald]

True, I use both Kingston and Samsung 1333Mhz and they work well together, :yep:

[Arclight]

More important for RAM in gaming is the latency. You generally see a CAS # listed with it's specifications, sometimes a more complete listing like 5-5-5-10. Cas is the first in that row, and those 4 values represent the most important timings. The lower the better.

For gaming, bandwith doesn't have that much impact, so if that other kit has lower latency it may well improve performance a bit. It's not going to be an awful lot though, RAM doesn't have that much impact, assuming you've got a half-decent kit to begin with.

With the modern i5/i7 CPUs the difference is even smaller; the memory controller is integrated on the CPU, rather than located on the Northbridge (the main "hub" on the motherboard, basically the chipset). There's an article floating about on AnandTech comparing different memory kits on a latest-gen i5: all the results came in so close that the difference can be explained by variations you get between benchmarks.

(oh, here we go: http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3/1)

AMD has been doing this for years, so I guess you'll see something similar on those platforms.


tl;dr: if the timings are tighter, swap it out and give it a shot. You'll have to benchmark or judge yourself if things improved.

* ah right, PCwizard (http://www.cpuid.com/softwares/pc-wizard.html) can give you feedback on the latency. Not the most intuitive interface, byut you can go to 'benchmarks' and find one for RAM latency.

[PapaKilo]

Something along those lines about RAM and speed..:


If you're asking about an Intel system, especially a Core 2, the CPU:DRAM
ratio should be 1:1...simple as that.
Just don't get confused by the quad-pumped FSB & the double-pumped memory.
Reduce them to their frequencies 1st...divide the FSB by 4, divide the RAM speed by 2.
Examples:
800MHz FSB / 4 = 200MHz frequency
1066MHz FSB / 4 = 266MHz frequency
1333MHz FSB / 4 = 333MHz frequency
DDR2-533 / 2 = 266MHz frequency
DDR2-667 / 2 = 333MHz frequency
DDR2-800 / 2 = 400MHz frequency
DDR2-1066 / 2 = 533MHz frequency

In other words, if you have a 1066MHz FSB CPU & have no intentions to overclock it,
all you really need is DDR2-533. If you use DDR2-667, DDR2-800 or DDR2-1066
with a CPU running at 1066MHz FSB, it should be underclocked to DDR2-533 speed.
It's not complicated, just run the CPU & RAM at the same frequency...that's all there is to it.

[Arclight]

Don't know if that's still really relevant, but it used to be something overclockers aimed for.

But yeah, running 1600MHz FSB and 800MHz RAM here. Latency is a fair bit lower than it was with my previous 1066MHz kit, but the current kit has tighter timings as well.

[PapaKilo]

Mine are also 800 MHZ with the same CPU frequency. But I never managed to make ratio 1:1 :nope: The last time I set RAM to work on 266 mhz PC failed to start at all. Had to open the box and pull out BIOS battery to drop to default settings.

[Arclight]

CPU frequency or FSB frequency? Cores actually run 3.4 here, it's the FSB that's at 1600.

The thing you're trying to sync is the busses, not really the end frequency. Depends on BIOS, but there's normally something like a "FSB strap" or ratio you can set for the RAM. On this board I can set the strap to 400MHz (after setting CPU to 400 manually), and on an older board I could set the "RAM ratio" or some such to 2. Both result in 800MHz RAM with a 1:1 ratio.

[PapaKilo]

I tried to decrease my RAM's Mhz from 400 to 266. Probably was some stupid idea if it didin't worked :doh:

[Arclight]

No think you want 400MHz; Since the DDR2 internal clock runs at half the DDR external clock rate, ...
http://en.wikipedia.org/wiki/DDR2_SDRAM

Basically it takes a 400Mhz external bus and uses 200MHz internal bus. Then some double-pumping magic takes place and you end up with 800MHz effective.

So with the bus at 400MHz, you end up with a synced 1600MHz FSB and 800MHz RAM.

[gammaphialpha]

Its better to use identical RAM. The conflict between 2 RAM can cause BSOD.