Need a little clarification on memory speeds.

Musafa

Junior Member
Dec 16, 2008
4
0
0
I recently purchased an Intel E8400 which surprisingly the FAQ on memory is based. Before I ask my question here's a list of some system specs I'm fairly certain pertain to my issue.

CPU: Intel 8400
System Board : GA-P35-DS3L rev2 (BIOS rev. F9b newest)
System Memory : G-Skill PC2-8500 2gigbytes Dual Channel 2x1gig (Part# F2-8500CL5D-2GBPK)
OS: Windows XP SP2 32bit

I read this in the FAQ;

"Let's take an E8400 Wolfdale dual-core, shall we? It has:
a multiplier of 9x
a FSB of 1333mhz
a speed of 3ghz.

Now, 1333x9 is 12ghz, which is definitely not the speed of your CPU (sorry)
To get the actually speed of the chip, divide the FSB by four.
1333mhz/4 = 333mhz.

Now, let's try again:
9x333=3.0ghz (2997mhz if you're picky)

So you need to use DDR2-667 RAM with this CPU at least. (667/2 = 333) "

Now I don't have any formal education with hardware, honestly my only experience is from watching my father tinker with computers. According to this my cpu/system board setup should be able to use my memory to its full capacity.

Now, right here is where I could be completely wrong and the rest of what I'm about to say is worthless but here is the actual problem.

Looking at CPU-Z it reports that my individual sticks of memory have a max bandwidth of PC2-6400 (400mhz) and in the timings table under EPP#1 it rates the frequency at 533mhz at the timings and voltages listed on the sticker on the memory its self. Additionally CPU-Z under the Memory tab lists the memory as single channel which made me double check whether or not I installed my ram in the correct slots and they are. Why would CPU-Z list the memory like this?

There's just so many conflicting numbers I've become overwhelmed please help me out.
 

Denithor

Diamond Member
Apr 11, 2004
6,298
23
81
Two things to keep in mind for memory. The CPU interfaces with the motherboard at four times the fsb (333*4 = 1333) which Intel likes to refer to as "quad pumped" for some obscure marketing reason. DDR/DDR2 memory runs at twice the fsb (Double Data Rate, get it?) or twice the fsb*memory divider.

Your memory is running with a 5:8 memory divider. Your system is at stock fsb (333) which gives 333*8/5 = 533MHz which when doubled (ddr) is functioning correctly at DDR2-1066 speed.
 

n7

Elite Member
Jan 4, 2004
21,281
4
81
Yes, speed is correct, though timings are looser than they need to be.

You can go into the BIOS & set it to 5-5-5-15 & voltage to 2.0 -2.1v if it isn't already.

But the real issue is why you are running single channel.

Usually you'd put the RAM in slots 1 & 3 or 2 & 4 for that to work.

Check your motherboard's manual if you are already in that sorta config but it's still not in dual channel.
 

DSF

Diamond Member
Oct 6, 2007
4,902
0
71
I have that exact motherboard and my RAM is running in dual-channel without any trouble. I'm trying to think of whether there's a setting in the BIOS to enable/disable dual channel, but I can't recall one.
 

Musafa

Junior Member
Dec 16, 2008
4
0
0
Yeah I have the RAM in slots 1 and 3 they're even color coded on the board and a triple check in the manual tells me this is correct as well. My system boots fine with either stick alone so I don't know whats up there.

As far as changing the voltages and timings my BIOS seems to think it knows better and doesn't really have any options to change it. I'm sure my BIOS does know better in the vast majority of decisions being made but it would be nice to have some input :)

 

n7

Elite Member
Jan 4, 2004
21,281
4
81
Not sure if they still do this, but you used to have to select CTRL + F1 in the BIOS to unlock the advanced options.

 

DSF

Diamond Member
Oct 6, 2007
4,902
0
71
Originally posted by: n7
Not sure if they still do this, but you used to have to select CTRL + F1 in the BIOS to unlock the advanced options.

Exactly. At the main BIOS screen press Ctrl+F1 before you go into the M.I.T. menu. Then all the options will be there. That said, I still don't think there was a setting to toggle dual channel.
 

Musafa

Junior Member
Dec 16, 2008
4
0
0
Did not know about the Ctrl+F1 stuff neat. I'll try that out in a little bit here thanks.