Mixing Corsair Ram on a K8V motherboard

[Mark Timerding]

Hello,

I am wondering if anyone can tell me how to do this.

I recently installed a K8V motherboard, Athlon 64 3400 cpu,
and 1 gig Corsair XMS TWINX1024-3200LLPRO COR ...
That leaves one empty ram slot on my mobo ... so, I have
two sticks of Corsair XMS PC2700 ddr ram (512mb ea)
left over from when this computer had an Asus A7N8X in
it. I decided to try an see if this computer would run with one
of the pc2700 sticks in it ... not that I need it, but why not?
Better than leaving it just lay there in the box as spare parts.
I checked on the Corsair website forums, and it is indeed possible
to mix this two rams (tho not totally recommeded by Corsair)
I installed one of the pc2700 sticks in the empty slot ... the
computer booted just fine, there were no crashes, errors or lock ups.
So now it was running with 1.5 gig ram, and no apparent errors.
I assumed, that the 2700 stick might drag down the speed of my
ram to 333mhz (from 400) but, when I ran Aida32 memory benchmarks
I was agast. The memory write speeds, and read speads were now
almost exaclty 1/2 of what they were. (from 1290 write to 650 write, and
from 2980 read to 1300 read) Obviously this was a lot more of a drop
than going from 400mhz to 333mhz.
Apparently I have to set something in the Bios? The posts I read on the
Corsair website were for doing it with a P4, and associated mobo ....
nothing specific for doing it on this AMD64 K8V.
In the summary listing in Aida32, with the extra ram added ... it lists my
system/cpu/ram comparable to a Athlon XP 2000 with pc2100 ddr.

Any advice out there?

 

[Ben Pope]

Hello,

I am wondering if anyone can tell me how to do this.

I recently installed a K8V motherboard, Athlon 64 3400 cpu,
and 1 gig Corsair XMS TWINX1024-3200LLPRO COR ...
That leaves one empty ram slot on my mobo ... so, I have
two sticks of Corsair XMS PC2700 ddr ram (512mb ea)
left over from when this computer had an Asus A7N8X in
it. I decided to try an see if this computer would run with one
of the pc2700 sticks in it ... not that I need it, but why not?

'cos it's not rated for 200MHz, and you are unlikely to require more than
1Gig.

Better than leaving it just lay there in the box as spare parts.
I checked on the Corsair website forums, and it is indeed possible
to mix this two rams (tho not totally recommeded by Corsair)
I installed one of the pc2700 sticks in the empty slot ... the
computer booted just fine, there were no crashes, errors or lock ups.
So now it was running with 1.5 gig ram, and no apparent errors.
I assumed, that the 2700 stick might drag down the speed of my
ram to 333mhz (from 400) but, when I ran Aida32 memory benchmarks
I was agast. The memory write speeds, and read speads were now
almost exaclty 1/2 of what they were. (from 1290 write to 650 write, and
from 2980 read to 1300 read) Obviously this was a lot more of a drop
than going from 400mhz to 333mhz.

Indeed. See below for possible explanations.

Apparently I have to set something in the Bios? The posts I read on the
Corsair website were for doing it with a P4, and associated mobo ....
nothing specific for doing it on this AMD64 K8V.
In the summary listing in Aida32, with the extra ram added ... it lists my
system/cpu/ram comparable to a Athlon XP 2000 with pc2100 ddr.

Any advice out there?

In AIDA, check what your RAM timings are for all the memory modules. If you
grab the SPD from the TwinX and compare to the PC2700 stuff, you may find
that your CAS latency has increased from 2 to as much as 3. This may
account for the differences you see. It's not all about MHz, but latencies
too.

I suggest you check your peak commit charge in Task Manager ->
Performance -> Commit Charge (K) to see how much RAM you need. If it's not
more than 1Gig, uninstall the PC2700 and be happy that you do not require
more than 1Gig of RAM. If it is over 1Gig, then decide whether or not to
get another 512MB module - you spent a lot of money on the TwinX, don't
spoil it by dragging it down with RAM of lesser ability.

I don;t think the Athlon64 3400 is Dual Channel, but if it is, then adding a
3rd module may prevent Dual Channel from working, which would explain the
50% drop.

Ben

 

[Mark Timerding]

I don;t think the Athlon64 3400 is Dual Channel, but if it is, then
adding
a 3rd module may prevent Dual Channel from working, which would
explain the
50% drop.

From what I found out, before trying this .. it's not ... that's why
I figured I'd give it a try. (I had assumed, because it wasn't, there
wouldnt be that major of a performance hit)

Thanks for the informative reply Ben ...like I said in my
orig post, I don't NEED to do this ... just that seeing as I
now have a A7N8X, populated with an Athlon XP 3000+ and
one gig of Corsair XMS ddr2700 just laying on the floor, going
to waste (damn, even including a Thermaltake Volcano 11+ cpu
cooler) ..... figured I'd try to see if I can put some of it to use.
Hoped I could at least put one lousy stick of the ram to use!
Apparently not ... the performance hits I referered to in my
orig post, is surely not worth it ... so I yanked that pc2700
out of this box ... (pending whether or not there may simply be
a matter of a simple bios setting needed or something)

According to your recommendation, my Peak Commit change
is 780mb .... which, I guess just documents that I do not
need the extra stick .. and even if it worked right ...I would
gain absolutely nothing by putting it in.

Altho I am not very good at it ... these computers are my hobby,
the absolute only thing I do or spend any money on. I think I am
the only person I know, that doesnt have 2 or 3 cars, buy a case
a beer a week, spend money on a bowling league, go to sporting
events ...(that isnt by choice as much, as the fact that seeing
as I am disabled with MS ...sitting at home, banging away on
my computer is more or less the only thing I do in life)

On a slightly related topic, for anyone interested that may
be thinking of the change (to an AMD 64) .... the gains so
far I have seen have not been all that signigicant over my A7N8X,
At least, in daily use of this computer. I've read that on severely
intensive cpu applications, like dvd burning, (which I do do
occasionally) I will see some major gains ... but, for the daily stuff
... there are gains across the board but perhaps not enough to justify
the expense of this upgrade.

One thing that does puzzle me (if not bother me) is that, so far,
on EVERY single benchmarking program I have run, Aida32,
SiSoft Sandra, PCPITSTOP, 3dmark 2001, 3dmark2003, and
Aquamark ... on every single one of them, this system scores
well UNDER a Pentium 4 2.6 gig (and up) .... be it data
transfer rates (on IDE or SATA), or video card performance ..
my scores are always at the top of the amd heap (except for
the AMD 64 FX51 and fx53) but always well under any of
the Pentium 4's. (with supposedly lesser rams, and video
cards) ... (my video card is a Radeon 9800 Pro) And that
makes me wonder, because I had always heard/read that the
AMD 64's give serious competition to the Pentium 4's and
absolutely blow away any of the ones under 3 gig.

But, I dont know ... I am running everything at defaults ....
nothing is tweaked or overclocked ... and maybe those
statements about competing with P4's, means IF your
AMD is overclocked.

 

[Ben Pope]

According to your recommendation, my Peak Commit change
is 780mb .... which, I guess just documents that I do not
need the extra stick .. and even if it worked right ...I would
gain absolutely nothing by putting it in.

Indeed. the Peak resets itself for each "session" so whenever you reboot,
you'll lose the peak.

Altho I am not very good at it ... these computers are my hobby,
the absolute only thing I do or spend any money on. I think I am
the only person I know, that doesnt have 2 or 3 cars, buy a case
a beer a week, spend money on a bowling league, go to sporting
events ...(that isnt by choice as much, as the fact that seeing
as I am disabled with MS ...sitting at home, banging away on
my computer is more or less the only thing I do in life)

Well they're my hobby too, but I also have a car (well, actually I don't, it
was stolen and torched on Sunday, but it will be replaced) which is pretty
good at eating up all available money

On a slightly related topic, for anyone interested that may
be thinking of the change (to an AMD 64) .... the gains so
far I have seen have not been all that signigicant over my A7N8X,
At least, in daily use of this computer. I've read that on severely
intensive cpu applications, like dvd burning, (which I do do
occasionally) I will see some major gains ... but, for the daily stuff
... there are gains across the board but perhaps not enough to justify
the expense of this upgrade.

I'd be suprised if DVD burning benefits from 64Bit.

It seems that gaming can benefit from the improved architecture, I'm not
sure if 64Bit helps significantly, but the lower memory latency most
certainly should.

Very few applications require 64 bit numbers so there is no gain in moving
to a 64bit architecture.

However, gor those consifering a new system, the price difference should
make the 64bit option considerable.

One thing that does puzzle me (if not bother me) is that, so far,
on EVERY single benchmarking program I have run, Aida32,
SiSoft Sandra, PCPITSTOP, 3dmark 2001, 3dmark2003, and
Aquamark ... on every single one of them, this system scores
well UNDER a Pentium 4 2.6 gig (and up) .... be it data
transfer rates (on IDE or SATA), or video card performance ..
my scores are always at the top of the amd heap (except for
the AMD 64 FX51 and fx53) but always well under any of
the Pentium 4's. (with supposedly lesser rams, and video
cards) ... (my video card is a Radeon 9800 Pro) And that
makes me wonder, because I had always heard/read that the
AMD 64's give serious competition to the Pentium 4's and
absolutely blow away any of the ones under 3 gig.

Hmm, seems a little odd. I wouldn't expect there to be a single
(real-world-esque) task that the 2.4 would outperform your 3400+

Disk transfers: maybe, but not by a significant amount.

But, I dont know ... I am running everything at defaults ....
nothing is tweaked or overclocked ... and maybe those
statements about competing with P4's, means IF your
AMD is overclocked.

Nope - take a look at Anandtech, you should find that their reviews show the
Athlon64 pissing on the 2.4 from a great height.

Ben