P4 800FSB choice for Corsair VS RAM?

Hi,

I've posted a few questions previously having to do with a possible
processor/RAM upgrade for my Asus P4P800 Deluxe mobo currently running a P4
2.2ghz 400fsb with 1gig of Crucial PC2100 in 2 sticks at a slight overclock.
I appreciate all the former suggestions.

Yesterday, while I'm visiting family in Southern California, I stumbled onto
a deal at a local Frys store that seemed too good to pass up on; it was on
Corsair Value Select RAM, PC3200, model #/type VS512MB500 -- I believe this
is Cas 2.5 stuff. The price, after rebates and sales tax will end up being
$130 for a gig as 2 sticks of 512MB. In order to do this I had to buy 1 of
the sticks and a relative bought another so dealing with the purchases and
the rebates will be a slight PITA, but I digress.

Presumably this stuff is not hugely overclockable, but then with a gig of
branded DDR 400 RAM for $130, one can't be toooooooo picky.

I'm going to order a fsb800 P4 processor to go with it; most rational
bang-for-buck choices seem to me to be either the 2.6 or the 2.8GHz.
versions. The 2.4 GHz P4 costs about the same as the 2.6 from what I can
see.

Firstly, which of these processors would you get with this RAM, and
secondly, what would be your expectations and/or strategy in trying to
modestly overclock them with stability and stock cooling in a
well-ventilated Aspire X-Alian case that has 6 case fans?

Any suggestions will be hugely appreciated!!!!!

Best,

ken

 

is the ram you bought recommended by ASUS? A good deal is only a deal
if it works.

Locust

 

The QVL list is pretty short, and I've seen posts in the Asus forum
referring to ram for this board that is not listed there.

I guess the proof is in the testing. Worst comes to worst, the RAM should
at least work at rated specs, or so it seems to me; I doubt it would be flat
out incompatible on a basis other than it being defective. Hopefully, it
could be overclocked to a smallish degree (~15%) or at least the bios could
be set so that it would run at stock specifications alongside a modestly
overclocked P4.

But then, what do I know?

ken

 

I'm afraid, Ken, you did not make a good deal.
There will probably no problem to run ONE single Corsair DDR module at
rated FSB speed of 200 MHz. But you will not be able to run the two modules
at dual DDR speed of 400 MHz. Even if you set the speed at 5:4, you stiil
could encounter problems in mem intensive applications. There is no question
of overclocking Corsair PC3200 above 400 MHz. If you want to run dual DDR
Corsair PC3200 at 400 MHz and cas 2 or 2.5, you should purchase Twin modules
(I'm sure they were no part of the promotion !!!). And if you want to
overclock, the only thing to do is to purchase PC3500, PC3700 or PC4000.
And in this case, Value Select is the lowest Corsair quality label, behind
C2 (cas2), LL (low latency) or Twin (paired). "Value" is here only related
to the purchase price.

 

El Jerid,

Please stop spreading this nonsense. Your odd notions of DDR and Dual
Channel have been disputed and refuted in several previous threads, and you
are handing out the same misinformation again.

I understand that your opinions are based on your experience with Corsair
LL, but they were specific to your system and you are mistaken to make such
sweeping statements that run contrary to the experience of many others --
not to mention the manufacturer's specs and independent reviews.

Corsair, Value Ram as well as the higher-end lines, is guaranteed for life
and will run at its rated speed of 200 fsb. That is exactly the same thing
as saying DDR 400 and PC3200.

Running two 512-meg sticks in dual channel at the rated speed should be no
problem, and many others have done so successfully. The same is true of any
decent memory brand.

You do NOT need TwinX or any other "matched pairs" of ram to run in dual
channel mode. Memory marketed that way carries a higher price tag because it
is supposedly pre-tested and guaranteed for dual channel. But there are lots
of folks out there, including me, who are running fine in dual channel --
and at 5:4 -- with no such guarantee.

Ken's new memory may or may not overclock much beyond 200, (some report 210
or 420 DDR at CAS 3,) but that isn't much of a hindrance. All he needs to do
is run it at 5:4, which will give him 250 fsb on the cpu while keeping the
ram in spec at 200 mhz at its SPD timings of CAS 2.5.

As for cpu choice, my pick would be the 2.6. At 250, the 13X multiplier
would give him a respectable 3.25 ghz. Anything more would be gravy.

At the same settings, the 2.4 would be at just 3.0 (and unlikely to get a
lot higher with that ram,) and the 2.8 at 3.5 (possible, but a bit of a crap
shoot.)

 

Hi Skid,

I have one more question which will follow these comments:

This group is really great! Thanks for your suggestions. Of course the
only reason I bought that Corsair Value Select RAM was the price; $130 for a
gig (as two 512MB sticks) of PC3200 DDR400 RAM is the cheapest I have seen
for any major brand's product. My sense when I bought it was that it was
"good enuf for my purposes," not that it was the "be-all and end-all of high
end RAM." Your post, Skid, confirms that we are on the same wavelength.

As for matched-pair sticks of DDR RAM, in response to the questions raised
earlier by Jerid, Corsair "markets" this RAM two ways, in the 512MB size:
part number VS512MB400 is a single stick, and VS1GKITMB400 are two sticks in
one box. Obviously the latter is intended for those souls who desire a GB
or a multiple of same on their system. I doubt that very many people buying
DDR400 RAM, which is relatively expensive, would do so without wanting dual
channel functioning if their mobo is capable of it.

Getting to my one remaining question, Skid (and others): I have now placed
my order with Newegg for the recommended 2.6 GHz. P4 800FSB CPU. I was
planning to use stock cooling, e.g. the fan that comes with the retail box.
The case is an Aspire X-Alien with 6 case fans. CPU idle temps with my old
2.2 GHz. P4 overclocked 15%, FSB=~460, VCore around 1.65, were about 29C,
highest operating temps I ever saw were 43 or 44C., with the stock P4 fan
and heatsink. Is it likely that I will need some sort of better fan for
cooling the P4 2.6GHz processor to the range of up to 3.25 ghz, or can I go
stock? What other fan choices should I consider or get to enable this
processor to perform stably at its best while not going beyond air cooling?
Or, should I settle for slightly less than 3.25GHz and stick with the stock
fan as necessary?

Thanks for all advice in advance!

Ken

 

Time will tell. Don't be surprised that your temps are higher with an
overclocked P4C. The stock cooler is usually fine until about 3ghz. After
that some people are happy with them and some want better coolers for longer
life and stability. I would say that if your new cpu doesn't get much above
60C at maximum load, you should be fine with the stock cooler.

My Abit IC7 is known to read about 10C high. I was getting 70C+ on a hot
summer day with no air conditioning with my 2.4 at 3.3. A $24 Vantec
Aeroflow trimmed that by 10C and is a little quieter.

My advice is experiment with the stock cooler. You won't know until you try
how high or how hot your cpu will run.

 

Hi Skid,

If, hypothetically, I was satisfied with ~3ghz from the P4 2.6 CPU, would
this effect the ratio for using Dual channel with the DDR400 el cheapo
Corsair RAM? If 5:4 is appropriate for 3.25ghz, does the same hold for
3.0ghz? Trying not to sound totally clueless, which bios setting controls
this ratio? The CPU won't come until at least Friday, and right now I'm
visiting family in another state so my PC is 1000 miles away and I can't
play with the bios for a couple of days!

Thanks!

ken

 

Yes.

First get the system up and running at stock settings. 13x200, 1:1. After
you're sure it's stable, you can play around. You're unlikely to get far at
1:1, every 10 mhz in fab buys you a measly 130 mhz on the cpu and the ram
will go belly up long before the P4C.

So go 5:4, and work up from 200 fsb in whatever increments your patience and
comfort zone allow. Your 2.6 is locked at a multi of 13, so 230 fsb gets you
a little under 3.0 and 240 gets you a little over. I just picked 250 as a
goal that should be attainable if the cpu and ram are at least average
performers.

To figure out where the ram is at 5:4 for any given fsb, just multiply by
..80. 250 is 200, 240 is 192. Sometimes when you underclock the ram you can
right tighter timings and gain a little bandwidth, but there are no
guarantees. MemTest86 is freeware that runs from a boot floppy and tests the
ram, generating errors when you're pushing it too hard.

For the cpu and ram, Sandra Max burn-in and Prime95 are good stress-testers
to guage stability when overclocking. If you can loop either of them without
crashing, you're golden.

You've got an Asus and I've got an Abit, so the settings will be different.
As you obviouly have online access, you can download the owner's manual from
Asus and check the bios guide at www.rojakpot.com to walk you through
anything the manual doesn't explain.

 

Hugely informative as always; thanks for taking the time to respond to my
questions, Skid!!!!

Ken

 

Hello Skid,
I've been working with computers for more than 20 years and I think I know
what I'm talking about, although I surely do not qualify myself as an
"expert".
When I purchase memory modules were the packaging mentions "XMS" (for
Extreme Memory Speed) and "3200C2", you will agree that I'm right to assume
that the "rated" speed in this case is 200 MHz at cas 2. In no case, the
module was able to run cas 2 at 200 MHz (but it could run at cas 2.5). And
even not at cas 2.5 when used in pair for dual DDR. Don' t tell me it's
specific to my system. I use an Asus P4P800, like Ken, and that was the
reason of my reaction.
And I feel angry about this because when Sandra reads the SPD information of
the modules, it reports "cas 2 at 167 MHz only, cas 2.5 at 200 Mhz".
For your info, and just to confirm what you called "misinformation" or "odd
notions of DDR", I finally made an agreement with the local reseller and
exchanged my both XMS PC3200 modules for Twin PC3700 (paired) modules (costs
me twice as much !). But now my system runs perfectly, without one single
crash, even overclocked at 240 MHz with mem ratio of 1:1, and at cas
3-4-4-8. And no, I'm not frustrated about this cas 3, because that's what on
the box and how it's advertised.

 

I'm glad you got your problem sorted. But your problems with getting one
particular brand and type of memory to run at its rated speed in dual
channel mode should not be stretched to make sweeping statements that
someone else will have the same problem with a different type of memory.

You also implied this time, as you have before, that you need twin modules
to run dual channel, which is not true; and that you need PC3500 or better
to overclock, which is not true.

I'm not trying to pick a fight. But when you make incorrect statements that
might mislead someone else you should expect to be challenged.

You said "There will probably no problem to run ONE single Corsair DDR
module at rated FSB speed of 200 MHz. But you will not be able to run the
two modules at dual DDR speed of 400 MHz."

You have no basis for such a claim. First of all, there is no difference
between running at 200 fsb and 400 DDR, they are the same thing. That's what
Double Data Rate means. It has nothing to do with one stick or two.

As for dual channel mode, that is a different thing altogether. It does
require at least two sticks, but it does NOT require "twin" or matched sets
as you suggest.

There are any number of people running mixed pairs of different speeds and
different brands in dual channel mode, though they need to relax the timings
and adjust the fsb to allow the slower stick to function properly.

Buying two sticks of the same memory from the same manufacturer will amost
always give you dual channel capability unless one of the sticks is faulty.

It is much more likely that Ken's memory will work at its rated speed in
dual channel than not, and that is the exact opposite of what you were
trying to tell him.

If you want to tell the world that your Corsair XMS 3200C2 won't work at its
rated speed in dual channel mode on your Asus P4P800, you won't get any
argument out of me.

But if you want to keep telling people that the same applies universally,
you can expect me to disagree. My experience, and that of many other people
as reported in multiple reviews and forums all over the net, says otherwise.

 

Hi Skid,

Just to close this discussion, and to reinforce my argumentation about
"rated speed", hereafter the Corsair SPD data as reported by CPU-Z:

CPU-Z version 1.20
Memory Modules Serial Presence Detect (SPD)

Module #1

General
Memory type DDR-SDRAM
Manufacturer (ID) Corsair (7F7F9E0000000000)
Size 512 MBytes
Max bandwidth PC3200 (200 MHz)
Part number CMX512-3200C2

Attributes
Number of banks 2
Data width 64 bits
Correction None
Registered no
Buffered no

Timings table
Frequency (MHz) 166 200
CAS# 2.0 2.5
RAS# to CAS# delay 3 3
RAS# Precharge 3 3
TRAS# 7 8


Module #2

General
Memory type DDR-SDRAM
Manufacturer (ID) Corsair (7F7F9E0000000000)
Size 512 MBytes
Max bandwidth PC3200 (200 MHz)
Part number CMX512-3200C2

Attributes
Number of banks 2
Data width 64 bits
Correction None
Registered no
Buffered no

Timings table
Frequency (MHz) 166 200
CAS# 2.0 2.5
RAS# to CAS# delay 3 3
RAS# Precharge 3 3
TRAS# 7 8

 

I also want to end the argument, but I don't see that the SPD printout above
proves anything. Here's how CPU-Z identifies my Buffalo Tech PC3700, which
uses labled Winbond BH-5 modules and is running at this moment at CAS 2 at
220 mhz:

CPU-Z version 1.20
Memory Modules Serial Presence Detect (SPD)

Module #1

General
Memory type DDR-SDRAM
Manufacturer (ID) Melco (7F7F7F8300000000)
Size 256 MBytes
Max bandwidth PC2700 (166 MHz)
Part number

Attributes
Number of banks 1
Data width 64 bits
Correction None
Registered no
Buffered no

Timings table
Frequency (MHz) 133 166
CAS# 2.0 2.5
RAS# to CAS# delay 3 3
RAS# Precharge 3 3
TRAS# 6 7
------------------------------

In other words, CPU-Z reads, sometimes accurately and sometimes not, what
the manufacturer (or reseller, in the case of Corsair and Buffalo Tech,
since neither makes their own modules) tells it to read.

Sometimes the manufacturer plays games. Crucial/Micron, for example, is very
conservative and rates their PC3200 at CAS 3, even though it can easily do
CAS 2.5 on most boards at 200 mhz and higher.

Others, like Corsair, advertise the lowest latency the memory can be
expected to handle. You say your CMX512-3200C2 won't run at CAS 2 dual
channel at 200 mhz, and so you say nobody else's will, either. In fact you
keep trying to tell people no PC3200 will work in dual channel at 200 unless
it is sold as a matched set and they need PC3500 and up to overclock. All of
that is demonstrably false.

If you'll go to the customer reviews of the same memory you bought at
www.newegg.com, you'll see 98 reviews. Most one of them rave about it
performing as well or better than expected, though a few feel -- like you --
they didn't get what they paid for. The first on the list has it running
dual channel at DDR450, and another person on the first page has it running
CAS 2 at DDR 454.

Either they are lying, or you are extrapolating your limited data from a
single system too far.

Another thing to be aware of is that there were initially a lot of
compatibility problems with motherboards using Intel Canterwood and
Springdale chipsets and specific types of memory. Corsair LL was infamous
for refusing to boot on occasion or giving erratic performance at less than
optimal settings.

It didn't take much investigation by end users and the engineers on both
sides to determine that slower memory was working fine and it was the
high-end low-latency stuff that was giving trouble.

Intel reprogrammed the generic bios files provided to motherboard
manufacturers, who then released their own bios updates that eased the
problem. On the other side, memory vendors like Corsair reprogrammed the
SPDs in some sticks to identify them as being slower than they actually were
in order to get by the intitial timing issues that were causing problems on
some boards.

The result was that people who left their ram timings set by SPD got
reliable, but slightly slower, performance. People who adjusted the settings
manually could often get them tighter, and faster, than the SPD numbers.

At this point, I don't know if anyone is still reading or cares much about
this topic.

But the bottom line is that bios settings and timings for memory are not set
in stone. Memory varies from batch to batch and stick to stick. People using
the same memory and motherboard often get widely different results, just
like people overclocking cpus.

If you don't get at least the performance you paid for and the manufacturer
promised, you should return it. If you get more, be grateful.

But don't try to generalize based on your experience with a single system,
especially when your experience varies from the norm.

 

skid, ive got a few questions for you

i have an asus p4u800 motherboard
intel p4 (northwood) mpga-478 2.8GHZ FSB 53

ive used cpu-z to see what my clock speed is running at and it tell
me, my multiplier is x21.0 and fsb 133.3MHZ and buss speed a
533.3MH

im using the value select corsair vs512mb400

so i take it this is running in single channel mode. and if i adde
the same module again. this will run in dual channel mode and the
run at the FSB of 400MHZ ??

also will i be able to over clock the machine at this point

if so what could i get out of it

also i have 2 memory sticks as the following
crucial 512MB, DDR 333 - CT6464Z335.16T 1
Winbond 512MB DDR 333 - w942508ch-6 1

is this package over clockable? if so! what could i be looking at

and would it be worth sticking to this or buying another cosair stc
and over clocking that instead