Just got a GA-P35C-DS3R with a Q6600 and some DDR2 8500 because the
box said it was supporting 1333MHz FSB and 1066MHz memory... Well, not
quite! It does support DDR3 8500 but only DDR2 up to 6400.
So, should I return my DDR2 8500 5-5-5-15 and get a set of DDR2 6400
cas3 or keep the DDR2 8500 and overclock it from the 800MHz the board
supports?
I'm not too sure how that works... Can I overclock the memory
seperately from the CPU? I assume not, it depends on the FSB speed and
muliplier, right?
So, what's your opinion? Keep PC8500 memory or get lower CAS PC6400?
'Wizfrog' wrote:
| Just got a GA-P35C-DS3R with a Q6600 and some DDR2 8500 because the
| box said it was supporting 1333MHz FSB and 1066MHz memory... Well, not
| quite! It does support DDR3 8500 but only DDR2 up to 6400.
|
| So, should I return my DDR2 8500 5-5-5-15 and get a set of DDR2 6400
| cas3 or keep the DDR2 8500 and overclock it from the 800MHz the board
| supports?
|
| I'm not too sure how that works... Can I overclock the memory
| seperately from the CPU? I assume not, it depends on the FSB speed and
| muliplier, right?
|
| So, what's your opinion? Keep PC8500 memory or get lower CAS PC6400?
_____
Things are not what they seem; unfortunately the explanation that will lead
to an answer to your questions is not very clear.
DDR2 8500 is also known as DDR2-1066 and is rated for a 266 MHz clock. The
1:1 CPU Clock : Memory Clock you usually see is with a 1066 FSB is actually
clocking the memory at 533 MHz (the CPU is quad pumped, 4 X 266 MHz; the
DDR2 Memory is clocked at 2 X the CPU clock So, if you overclock your CPU
with a CPU clock of 400 MHz (rather than the stock 266 MHz) and a 1:1 CPU
Clock : Memory Clock you will get a 50% CPU overclock while the memory is
running at DDR2-800/ DDR2 6400 equivalent. The motherboard manuals from
various manufacturers use various terminologies for the CPU Clock : Memory
Clock ratio and for the Memory Bus speed. The exact same effect is being
described, but the words used can be different (and confusing.)
You are going to be setting the Memory Clock speed manually; you can set it
to any speed you wish. All the manual for your motherboard indicates is the
SPECIFIED memory speeds. You intend to overclock, so you are not going to
be using the SPECIFIED FrontSide Bus speeds, and you will likely set your
memory to something other than ANY of the specified speeds.
If you look at the sample memory speed setting in the BIOS used in your
motherboard manual, the parameter is 667 MHz, or 1/2 of a FSB speed of 1333
MHz. This implies DDR-2 memory running with a clock of 333 MHz and that is
clocked at 2 X 333 MHz (1 : 1 CPU Clock : Memory Clock ratio) = DDR2-667
MHz/ DDR2 5400 equivalent!
You don't specify WHICH DDR2 memory you have (brand & model number), but it
is likely that it can use a higher than normal voltage (say 2.350 v) and
somewhat longer latencies to operate at DDR2-1066 levels and that it can
ALSO use a more normal voltage (say 1.850 v) and latencies like 4,4,5 when
operated at DDR2-800 levels.
I use Patriot DDR2 8500 / DDR2-1066 SLI memory with a 50% overclocked E4300.
I have operated the memory at equivalent speeds from DDR2-400 to DDR2-1200.
I find that the highest speed (a 1:2 CPU Clock : Memory Clock ratio) and
longer latencies give slightly better performance on SiSoft Sandra2007
benchmarks than DDR2-800 or DDR2-600 [a 1:1 CPU Clock : Memory Clock ratio]
with shorter latencies { ~ 5,8,8 vs. 4,5,5 }).
One thing to keep in mind is that there is as yet no official standard for
DDR2 memory faster than DDR2-800. 'SLI ready' memory is a standards
initiative by nVidia that adds overclocking parameters to Memory module
SPDs. I believe that Intel has a similar initiative.
Bottom line, you can use the full speed of your DDR2 memory to some benefit
(1:1 and 1:2 are not the only ratios usable on most motherboards.) Your
DDR2 8500 memory is likely to outperform any DDR2 6400 with your system, no
matter what the bus speed settings. If you look back a few months in this
newsgroup to March, April, and May you will find a long discussion of how
DDR2 memory relates to bus speeds and clocks for Intel Core2 Duo
motherboards.
So, keep your memory; if you feel the need to return something, I'd suggest
considering swapping for a nVidia 680i SLI chipset motherboard. Or not.
Phil Weldon
"Wizfrog" <googleaccount@wizfrog.com> wrote in message
news:1193093668.753368.222410@k35g2000prh.googlegr oups.com...
| Hello,
|
| Just got a GA-P35C-DS3R with a Q6600 and some DDR2 8500 because the
| box said it was supporting 1333MHz FSB and 1066MHz memory... Well, not
| quite! It does support DDR3 8500 but only DDR2 up to 6400.
|
| So, should I return my DDR2 8500 5-5-5-15 and get a set of DDR2 6400
| cas3 or keep the DDR2 8500 and overclock it from the 800MHz the board
| supports?
|
| I'm not too sure how that works... Can I overclock the memory
| seperately from the CPU? I assume not, it depends on the FSB speed and
| muliplier, right?
|
| So, what's your opinion? Keep PC8500 memory or get lower CAS PC6400?
|
Wizfrog wrote:
> Hello,
>
> Just got a GA-P35C-DS3R with a Q6600 and some DDR2 8500 because the
> box said it was supporting 1333MHz FSB and 1066MHz memory... Well, not
> quite! It does support DDR3 8500 but only DDR2 up to 6400.
>
> So, should I return my DDR2 8500 5-5-5-15 and get a set of DDR2 6400
> cas3 or keep the DDR2 8500 and overclock it from the 800MHz the board
> supports?
>
> I'm not too sure how that works... Can I overclock the memory
> seperately from the CPU? I assume not, it depends on the FSB speed and
> muliplier, right?
>
> So, what's your opinion? Keep PC8500 memory or get lower CAS PC6400?
>
You're in an overclocking group. The Q6600 (especially if you got a
revision G0) is going to do 3GHz with ease. (Check the Newegg reviews
to see the spread on overclock numbers.) Which means you'll be
overclocking by 25% on the FSB. So your memory can go higher as well.
Your 8500 sounds like a good match for doing stuff like that.
If you weren't going to overclock at all, then I'd be tempted to
return it and get the CAS3. But where is the fun in that :-)
That is like buying a sports car, and always driving exactly
at the speed limit.
'Wizfrog' wrote:
| I got some OCZ PC2 8500 1Gb Dual Channel SLI ready EPP
|
| PN: OCZ2N1066SR2GK
|
| Is that any good?
_____
Yeah, OCZ2N1066SR2GK is good, but you need a pair of modules for Dual
Channel to work (and the two modules should be matched as closely as
possible). Dual Channel DDR2 operation gives a slight performance increase.
Also, in case you read the OCZ Technology description, be aware that though
the BIOS must be SLI memory aware to USE the extended information in the
SPD, that is only of use for automatic recognition and automatic use of
DDR2-1066 memory; manually setting the DDR2-1066 voltages and timings are
still possible without the automatic function.
Phil Weldon
"Wizfrog" <googleaccount@wizfrog.com> wrote in message
news:1193098859.509803.324790@i13g2000prf.googlegr oups.com...
|I got some OCZ PC2 8500 1Gb Dual Channel SLI ready EPP
|
| PN: OCZ2N1066SR2GK
|
| Is that any good?
|
|
Wizfrog wrote:
> Thanks for the answer...
>
> So now I wonder why is the board manual saying it is designed for DDR2
> 800MHz and DDR3 1066MHz, if the DDR2 can go higher?
> I'm confused.
>
> Another question: how do I tell the rev. of my CPU? is it on the box?
> or in the BIOS?
>
The chipset has an official rating. The FSB to memory ratio is set
by the dividers in the chipset. If you are overclocking, you select
a memory speed like DDR2-800. Then, when you raise the input clock
to the CPU (by 25%), both the CPU and the memory speed rise
proportionally.
You could also start with a slower memory choice, assuming there is
a divider for it, and again overclock the FSB. Say you started with
the memory set to DDR2-667, then increased the CPU clock by 25%,
the memory would be running at DDR2-833 or so. So there is some
flexibility in the setup. But most of the rabid overclockers
I've run into, always like the "high flying RAM" and not the
low latency stuff. Whether a particular RAM is a good choice,
really depends on whether the chipset has the legs to allow
the other parts added to the computer, to do their jobs. That
is why it pays to read the reviews, to see if you started
with a DDR2-800 setting, and overclocked until the RAM was
running at 1066, that the RAM could actually run well there.
Overclockers want to max the speed on both FSB and memory.
So you want memory that is consistent with your overclocking
plan. The choice of motherboard reflects that - you'd want
to select a motherboard that will allow a Q6600 to be overclocked
by 25%, without cramping your style (like, no VIA chipsets).
For that reason, look to motherboard reviews, or read the
product reviews for the board, as posted by other customers.
If processors had totally unlocked multipliers, that would
allow much easier, independent overclocking of the processor
and the memory. Only having the FSB as an option, is second
best. The Intel processors do have a few multiplier numbers
of variation, but that was put there for supporting stuff like
EIST, as far as I know. Fiddling with the multiplier (dropping
it), allows attempts at raising the memory even higher. But
I doubt you'll really need that, if all you are doing is
trying to get your 25% like everybody else. The idea is to
get an overclock, that is stable, so you can actually use
the computer for something besides benchmarking :-)
You probably can support faster speeds with your motherboard, but you
need to set the faster speeds in the BIOS. Most only list 800 mhz as
supported, because DDR2 8500 isn't really a standard spec. That's why
you have to go into the BIOS and turn off the auto setting for the
memory clock. I know on my DG33TL that you can crank the memory
speed up for 1066mhz memory in the BIOS.... I just can't find any
timings that will work with my ballistic tracer memory.
So when I figure that out, I'll be good to go to. Find out as much
as you can about your motherboard.
That's the best advice I can give.
-John.
On Oct 22, 6:11 pm, "Phil Weldon" <not.disclo...@example.com> wrote:
> 'Wizfrog' wrote:
>
> | Just got a GA-P35C-DS3R with a Q6600 and some DDR2 8500 because the
> | box said it was supporting 1333MHz FSB and 1066MHz memory... Well, not
> | quite! It does support DDR3 8500 but only DDR2 up to 6400.
> |
> | So, should I return my DDR2 8500 5-5-5-15 and get a set of DDR2 6400
> | cas3 or keep the DDR2 8500 and overclock it from the 800MHz the board
> | supports?
> |
> | I'm not too sure how that works... Can I overclock the memory
> | seperately from the CPU? I assume not, it depends on the FSB speed and
> | muliplier, right?
> |
> | So, what's your opinion? Keep PC8500 memory or get lower CAS PC6400?
> _____
>
> Things are not what they seem; unfortunately the explanation that will lead
> to an answer to your questions is not very clear.
>
> DDR2 8500 is also known as DDR2-1066 and is rated for a 266 MHz clock. The
> 1:1 CPU Clock : Memory Clock you usually see is with a 1066 FSB is actually
> clocking the memory at 533 MHz (the CPU is quad pumped, 4 X 266 MHz; the
> DDR2 Memory is clocked at 2 X the CPU clock So, if you overclock your CPU
> with a CPU clock of 400 MHz (rather than the stock 266 MHz) and a 1:1 CPU
> Clock : Memory Clock you will get a 50% CPU overclock while the memory is
> running at DDR2-800/ DDR2 6400 equivalent. The motherboard manuals from
> various manufacturers use various terminologies for the CPU Clock : Memory
> Clock ratio and for the Memory Bus speed. The exact same effect is being
> described, but the words used can be different (and confusing.)
>
> You are going to be setting the Memory Clock speed manually; you can set it
> to any speed you wish. All the manual for your motherboard indicates is the
> SPECIFIED memory speeds. You intend to overclock, so you are not going to
> be using the SPECIFIED FrontSide Bus speeds, and you will likely set your
> memory to something other than ANY of the specified speeds.
>
> If you look at the sample memory speed setting in the BIOS used in your
> motherboard manual, the parameter is 667 MHz, or 1/2 of a FSB speed of 1333
> MHz. This implies DDR-2 memory running with a clock of 333 MHz and that is
> clocked at 2 X 333 MHz (1 : 1 CPU Clock : Memory Clock ratio) = DDR2-667
> MHz/ DDR2 5400 equivalent!
>
> You don't specify WHICH DDR2 memory you have (brand & model number), but it
> is likely that it can use a higher than normal voltage (say 2.350 v) and
> somewhat longer latencies to operate at DDR2-1066 levels and that it can
> ALSO use a more normal voltage (say 1.850 v) and latencies like 4,4,5 when
> operated at DDR2-800 levels.
>
> I use Patriot DDR2 8500 / DDR2-1066 SLI memory with a 50% overclocked E4300.
> I have operated the memory at equivalent speeds from DDR2-400 to DDR2-1200.
> I find that the highest speed (a 1:2 CPU Clock : Memory Clock ratio) and
> longer latencies give slightly better performance on SiSoft Sandra2007
> benchmarks than DDR2-800 or DDR2-600 [a 1:1 CPU Clock : Memory Clock ratio]
> with shorter latencies { ~ 5,8,8 vs. 4,5,5 }).
>
> One thing to keep in mind is that there is as yet no official standard for
> DDR2 memory faster than DDR2-800. 'SLI ready' memory is a standards
> initiative by nVidia that adds overclocking parameters to Memory module
> SPDs. I believe that Intel has a similar initiative.
>
> Bottom line, you can use the full speed of your DDR2 memory to some benefit
> (1:1 and 1:2 are not the only ratios usable on most motherboards.) Your
> DDR2 8500 memory is likely to outperform any DDR2 6400 with your system, no
> matter what the bus speed settings. If you look back a few months in this
> newsgroup to March, April, and May you will find a long discussion of how
> DDR2 memory relates to bus speeds and clocks for Intel Core2 Duo
> motherboards.
>
> So, keep your memory; if you feel the need to return something, I'd suggest
> considering swapping for a nVidia 680i SLI chipset motherboard. Or not.
>
> Phil Weldon
>
> "Wizfrog" <googleacco...@wizfrog.com> wrote in message
>
> news:1193093668.753368.222410@k35g2000prh.googlegr oups.com...
> | Hello,
> |
> | Just got a GA-P35C-DS3R with a Q6600 and some DDR2 8500 because the
> | box said it was supporting 1333MHz FSB and 1066MHz memory... Well, not
> | quite! It does support DDR3 8500 but only DDR2 up to 6400.
> |
> | So, should I return my DDR2 8500 5-5-5-15 and get a set of DDR2 6400
> | cas3 or keep the DDR2 8500 and overclock it from the 800MHz the board
> | supports?
> |
> | I'm not too sure how that works... Can I overclock the memory
> | seperately from the CPU? I assume not, it depends on the FSB speed and
> | muliplier, right?
> |
> | So, what's your opinion? Keep PC8500 memory or get lower CAS PC6400?
> |
the default voltage for DDR2 ram on this board is 1.85v.. I have
crucial Ballistix 8400 mem that would only post @ 800mhz... I did
further reading and found that in order for my memory to post @ 1066 I
had to have a min voltage of 2.20.. I upped my meme voltage by +.3
( careful the bios settings arent accurate ) got a mem voltage of 2.22
and voila... my mem booted @ 1066.
DDR2 8500 on overclocked 6400bus? 
Linear Mode
