P4P800 Deluxe - Memory question

[David B.]

Hi all,

For those of you who use this motherboard or similar, I am just wondering
what memory you prefer? It's been a few years since I last built a system,
and I have some catching up to do. I am looking for 512MB's total and have
been thinking about 2 stick of each:

1. Kingston HyperX (KHX3200/256) DDR400 (2-2-2-6) - Not on Asus memory
qualified DDR400 vendor list, but this is DDR400 / PC3200.

2. Kingston HyperX (KHX3500/256) DDR433 (2-3-3-7) - This is on the Asus
memory qualified DDR400 vendor list, but isn't this DDR433 / PC3500??? If
DDR433 is faster than DDR400, why do the memory timings seem slower? Also,
doesn't the motherboard manual say only to use PC3200, PC2700, or PC2100?

3. Corsair XMS (CMX256A-3200LL) DDR400 (2-3-2-6) - Not on Asus memory
qualified DDR400 vendor list, but seems to have the best benchmarks.

My goals here are for stability, followed by speed using a P4 2.4C cpu.
Thanks for your time.

David B.

 

[harry wong]

First off, throw out any benchmark articles that you've seen that were
written before July 1. Many of the types of memory tested (including
Corsair) used Winbond BH5 chips, which are no longer being made. These made
for really fast modules (even if you can't speak French, check out the
memory roundup at hardware.fr site and you'll see what I mean). The BH5's
are only available now as the REALLY high priced Mushkin black 2-2-2 or the
lower priced lower quality Buffalo modules from Newegg.

That being said:
1). don't waste your cash on 2-2-2 RAM, as the P4P800 seems to be happier
at 2-3-2-6 or 2-3-2-7.
2). Are you going to overclock your CPU? If so and want to use a 1:1
divider, you better get some high quality 3700 or the new PC4000 memory. But
if you want to overclock at 5:4 (or will just run the 2.4C at stock speeds)
why go any higher than PC3200?

But to answer your question, I wouldn't (and don't) use any of the Ram that
you mentioned. The Corsair LL now has Winbond CH5 chips so don't expect
miracles. I am totally unfamiliar with Kingston.I would suggest that you
check out the OCZ dual channel PC3200 modules also. I am using them
(OCZ400512ELDCK) with a 2.6c on this board (running at 3.2gHz, with a 5:4
divider and the Ram is running happy at 200 and 2-3-2-6. The best thing is
that you can get them for less than $130 for 2 x 256 at Directron.

One last thing- if stability is your prime concern, and you won't be
overclocking at all, why not get Crucial PC3200? Rock solid at stock speeds
(although at CAS3) and $110 for 2 x256.

Hope this helped.

 

[MWS]

http://www.crucial.com/store/listparts.asp?Mfr+Productline=ASUS++Motherb
oards&mfr=ASUS&cat=RAM&model=P4P800+Deluxe&submit=Go

 

[David-B]

Thanks Harry for your quick response. I think I am missing the big picture
here though. If I run a 800 Mhz FSB, it is actually running at 200 Mhz
(double quad pumped), which means the cpu is able to access the FSB 4 times
per cycle.

Now if I use DDR400, it actually runs at 200 Mhz, but operates 2 times per
cycle. So I am a bit confused as both how the RAM and FSB operate at 200
Mhz, but the cpu is sending/receiving data at 4 times per cycle and the RAM
at 2 times per cycle? How can one send at 4 times if the other is only able
to receive at 2 times? Is this why 2 sticks of ram are used for dual
channel?

Well I never thought about overclocking yet. I am just getting my feet wet
here and learning as much as I can. From what I gather, a 1:1 divider with
FSB at 200 Mhz translates to RAM running at 200 Mhz (DDR400), and the cpu
running at 800 Mhz (double quad pumped 200 Mhz), a divider of 5:4 with 200
Mhz FSB translates to the RAM running again at 200 Mhz, but this time the
cpu is running at 1000 Mhz (double quad pumped 250 Mhz). Are 1:1 and 5:4
primarily the only ratios for this board? I hope I understand this correct
now. My motherboard should be here sometime later today, and I am still
pulling my hair over all the memory options out there.

Also one more question... I thought AGP 8X was for 0.8 volt cards, yet the
manual says to use only 1.5 volt cards which are AGP 4X? Thanks again for
your time and help.

David B.

 

[jaeger]

Thanks Harry for your quick response. I think I am missing the big picture
here though. If I run a 800 Mhz FSB, it is actually running at 200 Mhz
(double quad pumped), which means the cpu is able to access the FSB 4 times
per cycle.

200 quad pumped.

Now if I use DDR400, it actually runs at 200 Mhz, but operates 2 times per
cycle. So I am a bit confused as both how the RAM and FSB operate at 200
Mhz, but the cpu is sending/receiving data at 4 times per cycle and the RAM
at 2 times per cycle? How can one send at 4 times if the other is only able
to receive at 2 times? Is this why 2 sticks of ram are used for dual
channel?

DDR400 runs at 200MHz, with 2 data fetches per cycle. This means the
clock speed is effectively 400MHz. On the P4P800 this is doubled again
by the dual channel memory controller, which is how you get a 800MHz
memory speed synced with an 800MHz fsb. Don't get hung up on HOW they
all arrive at the rated speeds. The distinction between 200 DDR and 100
QDR is irrelevant to end users.

Well I never thought about overclocking yet. I am just getting my feet wet
here and learning as much as I can. From what I gather, a 1:1 divider with
FSB at 200 Mhz translates to RAM running at 200 Mhz (DDR400), and the cpu
running at 800 Mhz (double quad pumped 200 Mhz), a divider of 5:4 with 200
Mhz FSB translates to the RAM running again at 200 Mhz, but this time the
cpu is running at 1000 Mhz (double quad pumped 250 Mhz). Are 1:1 and 5:4
primarily the only ratios for this board? I hope I understand this correct
now. My motherboard should be here sometime later today, and I am still
pulling my hair over all the memory options out there.

A 1:1 ratio(not divider) means the RAM will run at whatever the fsb is.
5:4 simply means the RAM speed is running at .8 x the fsb. So if you
want to run a 250 fsb with PC3200(DDR400) RAM, a ratio of 5:4 allows it.
250 * .8 = 200. 4:3(.75) is also there. Which ratios you get depends
on your fsb. Over 800 you get 1:1, 5:4, and 4:3. Under that(I'm pretty
sure) you get 1:1, 3:4(1.33), and 4:5(1.25).

Also one more question... I thought AGP 8X was for 0.8 volt cards, yet the
manual says to use only 1.5 volt cards which are AGP 4X? Thanks again for
your time and help.

AGP 8X will work, the voltage conversions are not something to be
concerned with unless you try an old 3.3v card. Which you should not do
since your mobo would die. Some Asus boards automatically protect you
from this, the P4P800 does not.

 

[David B]

200 quad pumped.

Oops... meant to say quad pumped, not double quad pumped. Thanks!

DDR400 runs at 200MHz, with 2 data fetches per cycle. This means the
clock speed is effectively 400MHz. On the P4P800 this is doubled
again by the dual channel memory controller, which is how you get a
800MHz memory speed synced with an 800MHz fsb. Don't get hung up on
HOW they all arrive at the rated speeds. The distinction between 200
DDR and 100 QDR is irrelevant to end users.

Ok. Makes sense.

A 1:1 ratio(not divider) means the RAM will run at whatever the fsb
is. 5:4 simply means the RAM speed is running at .8 x the fsb. So if
you want to run a 250 fsb with PC3200(DDR400) RAM, a ratio of 5:4
allows it. 250 * .8 = 200. 4:3(.75) is also there. Which ratios
you get depends on your fsb. Over 800 you get 1:1, 5:4, and 4:3.
Under that(I'm pretty sure) you get 1:1, 3:4(1.33), and 4:5(1.25).

OK. I understand this now. So actually I could overclock somewhat with
PC3200, but if I used faster PC3700 or PC4000 I'd have better results?

AGP 8X will work, the voltage conversions are not something to be
concerned with unless you try an old 3.3v card. Which you should not
do since your mobo would die. Some Asus boards automatically protect
you from this, the P4P800 does not.

Ok. Sounds good then. Thanks for your help. I appreciate it.

David B

 

[harry wong]

I think folks should invest in a really good PSU so as not to fry the memory
that they currently have.

 

[jaeger]

Thanks for the OCZ memory advice. I checked out the OCZ400512ELDC-K memory
at Directron and it is $34 cheaper than what Newegg wants. They also have
OCZ400512ELDCPE-K RAM which is only $15 more. Do you think it is worth it?

Also, OCZ is not on the Asus DDR400 memory qualified vendor list. Is that
really a big deal as I have been reading good reviews about OCZ? And
finally if you look at that list, some memory can only be used as one pair
in 2 slots only, but you cannnot use 2 pair in 4 slots. Why is that, and
how do I tell with this OCZ memory? Thanks again.

No, no, no! Avoid OCZ! RAM is NOT where you want to save money by
cutting corners. They are a company with a history of poor service and
shady practices. Some claim they've changed, I'm not so sure. Why
spend money to find out? Lately they've been remarking their chips as
faster than they actually are...is that a company you want to deal with?

 

[David B]

No, no, no! Avoid OCZ! RAM is NOT where you want to save money by
cutting corners. They are a company with a history of poor service
and shady practices. Some claim they've changed, I'm not so sure.
Why spend money to find out? Lately they've been remarking their
chips as faster than they actually are...is that a company you want to
deal with?

So which PC3200 memory would you prefer? I have been looking at Crucial,
Corsair, Kingston, and now OCZ. My main goal here is stability, followed by
some decent overclocking potential.

 

[jaeger]

So which PC3200 memory would you prefer? I have been looking at Crucial,
Corsair, Kingston, and now OCZ. My main goal here is stability, followed by
some decent overclocking potential.

Out of those, Corsair. It might cost a bit more up front, but over time
the cost will be irrelevant. Remember though, when OCing a 865/875 you
really don't need anything over 3200. Your overclocking will be on the
CPU and mobo. So if money really is an issue, get the Crucial. Top
quality, but it's pretty much going to want to stay at stock...which
again is fine.

 

[daver201]

Out of those, Corsair. It might cost a bit more up front, but over
time the cost will be irrelevant. Remember though, when OCing a
865/875 you really don't need anything over 3200. Your overclocking
will be on the CPU and mobo. So if money really is an issue, get the
Crucial. Top quality, but it's pretty much going to want to stay at
stock...which again is fine.

I posted too soon. I just read in another post that you preferred Corsair
and Mushkin. I was looking at TWINX512-3200LL and TWINX512-3200LLPT
earlier. They are the same price and look the same except for different
heat spreaders. It sure seems like memory is the most difficult component
to decide on...

 

[David B]

I posted too soon. I just read in another post that you preferred
Corsair and Mushkin. I was looking at TWINX512-3200LL and
TWINX512-3200LLPT earlier. They are the same price and look the same
except for different heat spreaders. It sure seems like memory is the
most difficult component to decide on...

whoops... somehow my name showed up as daver201

David B