1066Mhz RAM :confused:

[sadeyx]

Hi!

I have read through the FAQ's and some of it makes sense, but then some of it seems outdated, so im sorry if my questions are answerd elsewere.

Recently Purchased
Asus P5N-T Deluxe nForce 780i (Socket 775)

with

Crucial Ballistix Tracer 2GB (2x1GB) DDR2 PC2-8500C5 1066MHz Dual Channel Kit (BL2KIT12864AL1065)

CPU: P4, 3.46HT
GeForce 7900GTO.

I dont usually like to fiddle around with BIOS settings, but with everything on 'auto' my memory only reports 800MHz

I read on the reviews that people are "pushing" 960MHz..

My questions are:
1] My board supports 1066MHz RAM, so why doesnt it detect it as such? and must I really start looking at the overclocking options to attain this speed?

2] I've read about the tCL, tRCD, tRAS and CMD settings and that most people are putting this ram into 4-4-4-12 @ 2.2v.

My board has all these options set to 'auto' ! - Is my board good enough to know the right settings or should I again manually enter them?

3] If im going to be digging around in these settings I may as well learn what they all are. Under my memory settings I also have the following "advanced options" which I cant seem to find out what they mean and if its worth adjusting:
tRRD - tRC - tWR - tWTR - tREF - tRD - tRFC - Async Latency.

4] I hear nightmare stories about people flashing motherboads with updated software, should I do this flash upgrade as a matter of course (like updating graphics card drivers) or should I leave it unless I really have to.

Thanks!

SADE-yX

 

[Hen_Dawg]

Welcome to OcUK dude.

It's pretty save to update BIOSes on modern Mobos but that's probably now why the RAM shows up slow.

I recommend setting the 4-4-4-12 manually just to be sure. I don't know why it would come up at that speed.
Is that what CPU-Z tells you, or in the BIOS?

 

[Boah]

CPU: P4, 3.46HT

I assume you mean a Pentium 4 3.4GHz of some sort.

1] My board supports 1066MHz RAM, so why doesnt it detect it as such? and must I really start looking at the overclocking options to attain this speed?

The CPU is an 800MHz FSB CPU, but the FSB is "quad-pumped" so the actual bus clock is 200MHz. The bus clock is the base speed the memory "operates from", in other words it is the basic element in how much data it can transfer, which is "how fast it runs". Since DDR is "dual-pumping" data to and from the bus, the effective memory speed at a bus of 200MHz is 400MHz.

DDR2-1066 (PC2-8500) would require a bus clock of 533MHz (2x533=1066) to run full speed on a 1:1 ratio between the bus and the memory. There is no motherboard that offers this sort of bus speeds yet as far as I am aware (the quad-pumped FSB would be ~2133MHz), and in any case that's not compatible with the CPU you have (avoiding overclocking for now).

Running your RAM at a 1:1 ratio to your FSB would mean that the RAM would run at an effective memory speed of 400MHz (1x2x200MHz). Running RAM:FSB at a 2:1 ratio means the memory is running at 800MHz (2x2x200MHz). 3:1, however, would mean 3x2x200MHz (1200MHz), which is faster than its rated speed.

To reach memory speeds of 1066MHz with a bus clock of 200Mhz (FSB 800MHz) you need to run the memory ~2.66 times faster than the bus clock (2.66x2x200MHz = ~1066MHz). This is RAM:FSB at roughly an 8:3 ratio.

This is most likely not an option on the board. In other words it is probably not able to run the memory that much faster than the bus (alternatively this particular divider may not be an option). Therefore the 'Auto' setting figures out the closest/best match and uses this (2:1) and runs the memory as close to its rated speed as possible (800MHz). If this is the case, overclocking the bus is the only option to attain a speed closer to or equal to its rated speed.

Common RAM:FSB dividers are 1:1 (1.0x), 4:3 (1.33x), 3:2 (1.5x) and 2:1 (2.0x). To reach RAM speed of 1066MHz those dividers would respectively need bus clocks of 533 (FSB 2133), 400 (FSB 1600), 355 (FSB 1421) and 266 (FSB 1066).

If those dividers are the only ones available to you in your BIOS, then you would need to run the bus at 266 on a 2:1 divider - but your CPU has a bus clock multiplier of 17 (200MHz x 17 = 3.4GHz), which means that it would run at 4.5GHz (266 x 17). If that sort of overclock on the CPU is possible, I would have thought you're certainly looking at a pretty hefty cooling system.

Of course, you can go closer to the rated speed without actually reaching it (e.g. bus 233MHz = FSB 932MHz = CPU 3.9GHz = RAM 932MHz (2x2x233)), but you're still into overclocking territory.

Hmm.. does that make any sense? I think it does, but it's late and the brain has pretty much packed in

 

[sargatanas]

Just so you know there was a 3.46Ghz P4 released so it may well be one, with a 1066FSB so itll need a 1:2 divider. if you have a 780i board you really should get a new core 2 cpu, even something like a 2200 would be faster than the P4 extreme.

 

[Boah]

Just so you know there was a 3.46Ghz P4 released so it may well be one, with a 1066FSB so itll need a 1:2 divider. if you have a 780i board you really should get a new core 2 cpu, even something like a 2200 would be faster than the P4 extreme.

Ah, you're right, there was a P4 Extreme 3.46GHz for 1066FSB. That's probably the one, and a RAM:FSB 2:1 should do it. I would've thought that it would find that with 'Auto', but perhaps not (and it's picking 3:2 instead, which runs it at ~800MHz RAM speed).

 

[Admiral Huddy]

Good post Boah


In a nutshell, (directed at op) you are confusing the effective FSB of the CPU with the effective FSB of the system. They are not the same thing as Boah has described.

It might be worth giving this a read too.

http://www.huddysworld.co.uk/Techpages/PCZone_TechieTalk_1.shtml


I have to ask however, why you've bought PC2-8500 memory if you don't intend "to fiddle" with the BIOS.

 

[Hen_Dawg]

If you have a 780i board you really should get a new core 2 cpu, even something like a 2200 would be faster than the P4 extreme.

It's true, even a £50 E2180, E2200 or similar will far outperform the P4 at stock speeds (see example here) while using less power, making less heat and would likely reach near 3Ghz speeds with a £15 cooler and a few changed settings in the BIOS.

Like Huddy I have to ask, why you've bought a performance/overclockers board if you don't intend "to fiddle" with the BIOS and overclock? If you decide to then there's plenty of help here to make sure it goes fine

 

[sadeyx]

Thanks for the welcome I've actually been a customer of OcUK for years now, but never needed to get any specific technical details.

Excelent replies! thank you for taking the time to explain it to me, some of it I knew but my knowledge is out dated so its worth the refresher.

Yes, my processor is the 3.46HT Extreme, The system was originally an Alienware (I know I know, more money than sense) and at the time 1066FSB was brand new, I was aware that I needed a 1066MHz FSB processor and if anything, Alienware know their stuff.

I bought this board since its 1333 (will be buying a new CPU sometime) and know I need a 1333 CPU to go with it.

But the other reason I got this board :- http://www.overclockers.co.uk/showproduct.php?prodid=MB-261-AS

is because it quite clearly states
"- DDR2 1066/800/667 MHz Dual channel memory architecture"

So naturally I picked some 1066 RAM to go along with it!... Nowhere does it state that I must "fiddle" with the BIOS or that these speeds are only attain from overclocking

remeber: overclocking by defination is basically asking hardware to do something its not meant to do! (as such isnt coverd by the warranty) Everything is advertised as 1066 compatible! so I have to ask in return.. if the RAM states its 1066 and the Motherboard states 1066 compatible why should there be a problem? I dont WANT to overclock and thats the reason I bought these items.

If these speeds are indeed only attainable by overclocking then surly there is a breach advertising conduct here.

 

[Hen_Dawg]

remeber: overclocking by defination is basically asking hardware to do something its not meant to do! (as such isnt coverd by the warranty)

Actually there are many manufactures who allow overclocking speeds and pushing extra volts under warranty.

But yes, I understand your right to just plug it in and expect it to work at given speed (Especially given the price of that mobo)

There were some motherboards (before BIOS updates) who needed you to put some cheap RAM in to boot first time before it ever recognised some higher performing stuff.

Sadly, building your own means you're gonna come up against these things. I'm not very knowledgeable on the CPU - FSB relationship by any means but I think they are saying the old chip is the reason the RAM is running slower.
Right guys?

 

[hterag]

Nice post Boah, I was about to post a few questions related to that myself, I think you've answered it all, thanks.

 

[sarge78]

sadeyx, nothing is wrong.

As Boah said

Memory (DDR) FSB is doubled (x2)
CPU FSB is quad pumped (x4)

Your CPU is running at 266Mhz (or 1066 as adversised) and I think most motherboard default settings run a 1:1 memory divider. This means the memory is running 266Mhz too (or 533Mhz)
As stated above you'll need to set the divider to 1:2 for the memory to run at 1066Mhz. While this is not overclocking I don't think you'd see any real world gains....?

When you buy a newer 1333 processor the main FSB will then effectivly be 333Mhz, so your memory needs to be capable of 666Mhz speeds.

1066 memory is for hardcore overclockers only (CPUs need to get to 2133 before you need it in standard machines)
________
Herbal vaporizers

 

[sadeyx]

As stated above you'll need to set the divider to 1:2 for the memory to run at 1066Mhz. While this is not overclocking I don't think you'd see any real world gains....?

If there are no real world gains, why would a hardcore overclocker bother? Many years ago when money was tight I did do a lot of overclocking, but id only overclock something if there was a benefit... no point in risking hardware but a minor benefit.

When you buy a newer 1333 processor the main FSB will then effectivly be 333Mhz, so your memory needs to be capable of 666Mhz speeds.

How can I tell if my memory is 666MHz capable?

http://www.overclockers.co.uk/showproduct.php?prodid=MY-114-CR

There is nothing there indicating this, it just says 1066..

1066 memory is for hardcore overclockers only (CPUs need to get to 2133 before you need it in standard machines)

I'd have to say im a little disapointed, Yes I've purchased a board which should keep me going for a long time, which is nice! and I am a believer of investment into good quality product. But I've bought memory which, for all intense purposes doesnt run at the advertised speeds (even if I bought a 1333 processor)

Knowing this I would have gone for cheaper RAM and possible bought more, or kept the saving for a processor.

Its probably no one elses fault but my own, but I dont make purchases likley and on every website I compared there was no indication on the product description, not even a slight hint.

Anyway, enough of my moaning, I'll set the RAS and CAS stuff and wait until I upgrade the CPU before attempting anything fancy!

I appreciate your replies and explanations.

SADE-yX

 

[sarge78]

How can I tell if my memory is 666MHz capable?
There is nothing there indicating this, it just says 1066..

It can run upto speeds of 1066Mhz (and beyond) so running at 666Mhz is like driving a ferrari at 40mph, something it can do quite easly!

If there are no real world gains, why would a hardcore overclocker bother?

Many people push the FSB to 500Mhz+ (see the latest wolfdale thread). To do this the memory needs to keep up and thats where the fast stuff comes into play.

For example you overclock your system with a FSB of 533Mhz. Your memory would be running at its designed speed, while potentially your CPU would be running @ 7Ghz with its 13 multiplier!!!!!

Knowing this I would have gone for cheaper RAM and possible bought more, or kept the saving for a processor.

I wouldn't worry, @ ?70 its cheep enough and you won't have to buy faster stuff when you upgrade the cpu.
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[Admiral Huddy]

..snip.

did you read my link ?