Techy Questions: May Need Alot of Explaing Please!

[Accendo]

Hi there guys my questions are:

1) CPU;
-How does the CPU clock speed between 2 devices differ so? e.g. A has 3GHz and B has 2.4GHz -- Would the 3GHz be straightforward 25% faster than 2.4GHz?

-How does CPU bus speed affect the speed of the entire processor?

-How do Multiple Cores really differ? Because I see Duo Core Intels at similar prices to Quad Core Intels which is odd seeing as Quad = 2x more power than a Duo so even at 2.4GHz a 4x is running at 9.6GHz while a Duo is running at 6.0GHz right... -- I assume this is very wrong because I've been told Video Games can only use 2 cores ATM but would it better to go for 2.4GHz x4 for £150 or 3.0GHz x2 for £120 PLEASE Help!!!



2) RAM -- This is most important because I really can find ANYTHING recent on this :S;
-How does CAS Latency and the 4 digits work / what does it mean? e.g. 4-4-4-12 << What does THIS mean because I read some articles from like 2004 and that was very different RAM but it didn't talk so much about it... So would 667MHz 3-3-3-12 be better than 800MHz 5-5-5-12?

-What does Memory Speed effect? You may already answer this in the above question but I thought I'd put it here to cover all my bases!

-FINALLY, what is the point in the GB on RAM when it's the MHz that influence speed? Also are the GB more important or not that the MHz?

I'm thinking I went a bit technical here but thats why I am here on this technical forum -- I am nigh on BEGGING for help here lol -- I have spent too long trying to find out how to understand how to measure the power on RAM and CPU's by looking at these stats so please be someone here who can help me OR link me to some technical article I have missed while searching over google.

Yours Very Sincerely: Ryan T

[danroyle]

1, a quad core @2.4ghz today in 99&#37; of games would be slower than 2x3.00ghz but long term the quad core would be better plus you can overclock it to 3ghz on air
bus speed is an important factor
2x3ghz cpu if one had 1333fsb and the other 800fsb the first would be slightly faster also cache plays a part too the higher the better as this is essentially the buffer so the bigger the buffer the more you can store in it as it transfers over so less chance of slowdown etc

2,
memory latency and speed depends on cpu amd cpu's have always been more reliant on low latency aka 3-3-3-12 were as intel prefers higher bus speed

so if you had an amd x2 6000 cpu you would be better off with some cas 4 800mhz ram but if you had an intel core2/quad then some cas 5 ram would be fine and you would be better off with 1066 ram

a load of overclockers will disagree with me on the ram probably as 800 popular here but if you look at raw performance at stock speed 1066 mhz is better for intel

so in summary long term quad core short term buy core 2 duo
and memory low latency amd faster speed intel

[peterb]

Good questions - and there are others better qualified than me to answer them, but I'll kick off...

CPU - Yes in rtheory two identical processes running on two CPUs, where one is 25&#37; faster than the other would run 25% quicker - however there are other factors that come into play, and it assumes that all other components in the system are capable of operating at the faster speed. However a computer dpes not just have one process running - there are many processes running simutaneously (well, on a single core processor they are actually multiplexed - each process has dedicated use of the processor for a small slice of time) so that comes into play too - while the processor is faster, that speed increase may not affect all processes linearly - however in general terms, using a faster processor will result in a faster system.

The CPU has an internal bus and an external bus (actually several). A faster internal bus means that data moves round the processor faster, so there are fewer internal delays. The external buses include memory, Input/output and a control bus (this is a very generic explanation) and these spedds are run at defined speeds as they interface with other peripheral devices - hard drives, graphics cards etc. So the faster the external bus, the faster the system will run, provided the peripheral devices attached to it are capable of running at that speed.

Multiple cores are more complex. Each core is a CPU in its own right - but sharing common resources, so the software that the CPU is running needs to be optimised to run on the mutiple cores. Whereas a single core runs mutiple process by multiplexing, then a mutiple core can run two processes simultaneously, or two parts of the same process simultaneously - but then there are overhaeds such as synchronising the two, so the design is quite complex, and an additional load on the operating system kernel. Games tend to use a lot of low level calls to the processor (for speed) so they have to be optimised to use multiple cores for best performance, but we are now getting into the realms of optimised compilers...

Memory

Some of the obverclockers (to whom CAS figures are bread and butter!) are better placed to advise - or a Google search will provide information, but basically think of memory as a two dimensional matrix, with columns and rows. To address any one element on the matrix, the corresponding row and column need to be addressed simultaneously. When that cell is active, data can be read or written to it. However the cells are volatile and so they need to be constantly addressed or STROBED. CAS stands for Column Address Strobe (and you might guess that there is a RAS - Row address Strobe. The latency referes to time delays in applying and refreshing the cells.

Gb refers to the amount of memory or storage. MHz refers to the speed that the memory can be addressed.

Basically the system needs to be balanced. Memory that is two slow for a system will result in memory errors, degradation in performance and/or a system that won't run. Increasing the specification in a system that is running OK won't result in an improvement in performance unless the operating parameters of the system are changesd - usually in the bios - but again we are straying into the province of the overclockers.

I am aware that I haven't answered all your questions - asin whicjh is best - partly because I am reluctant to specify one thing over another without knowing more background, but I hope that I have given enough general information to understand the terminolgy to do some research of your own.

I hope others on the forum will offer their tuppence worth on specifics that I have not addressed.

[Accendo]

Thanks alot for the insight you guys gave, so I should go for 800+ Mhz for my Intel CPU...

Thanks!!!

[Salazaar]

One of the best things to do would be to post your proposed system spec and what you want to do with it (i.e. gaming or whatever) in a new thread and let people criticise the hell out of it.

Or just read a few of the millions of threads where people have already done this

[Disturbedguy]

I know Accendo aka Ryan.

I dont know his entire spec, infact all I can tell you is that its going to be for gaming mainly i think.

As for spec wise, I think he is going to be basing it around the Mobo I have (Check My System) as for the rest im not 100&#37; sure, ill find him online and bug him to come reply.

[Lucio]

I know Accendo aka Ryan.

I dont know his entire spec, infact all I can tell you is that its going to be for gaming mainly i think.

As for spec wise, I think he is going to be basing it around the Mobo I have (Check My System) as for the rest im not 100% sure, ill find him online and bug him to come reply.

Your spec is good I've got similar, Q6600 overclocked to 3Ghz without even thinking about it, temps at a guess 45-50 degrees under load (I get mildly warm air blowing over my feet)

[MSIC]

What does Memory Speed effect?

The most important thing (from what i understand) is that it is at least fast enough to match the CPU bus frequency, so that the CPU isn't having to wait for the RAM to 'pick up' data and carry it along. As long as both are balanced (as mentioned above) then that works well.
Where it becomes a little complicated is where you have to remember to distinguish between arguably 'true' bus speeds and the effective speeds, i.e. DDR memory (and DDR2, DDR3 etc etc) carry data on both the rising and falling edge of current (or something far more technical than that). So a 'real' speed of 400Mhz gives an effective DDR speed of 800Mhz.
Intel chips, famously starting with the Pentium 4, have a Quad pumped bus, so a 'real' 200 Mhz Front Side Bus has an effective 800Mhz speed. In addition to this, modern motherboards allow for RAM to be installed in pairs to once again double the bus (or something like that), so a real 400Mhz RAM gives a DDR speed of 800Mhz and an overall (if inserted correctly in pairs) speed of 1600Mhz.

In practice, RAM runs faster than CPU bus speeds, which is fine, so nearly any RAM is good enough for any CPU. Unless you want to get in to overclocking, then it gets more complicated.....

FINALLY, what is the point in the GB on RAM when it's the MHz that influence speed? Also are the GB more important or not that the MHz?

I always like the analogy of builders, bricks, and wheelbarrows.
If you want to move more bricks you could add more builders but soon they would run out of spare wheelbarrows. You could increase the physical size of wheelbarrows but soon they'd be too heavy to carry. Or you could ask the builders to run with the barrows quicker, but soon they'd start to make mistakes and bricks would fall out.
You can decide what analogy matches what computer definition, but you get the idea...

Seriously though, if you are working with a large piece of data (say, a RAW photograph that is 1000MB in size) and you have 2GB of RAM, then soon enough once you start adding layers and effects to the photo you'll very soon use up all free RAM and start accessing windows page file (ie the physical hard drive used as virtual memory). Doesn't matter how fast your RAM is, once you start accessing the hard drive then you..........will..........start.................slowing...............................down.
What matters is that you have enough to meet your needs.
My personal opinion, but i feel strongly on this, is that you should always buy more of the slower stuff than less of the faster stuff (unless you specifically know you need otherwise).

[Disturbedguy]

not OC'ed my CPU xD but thanks lucio runnings sweet as a nut..feels good xD

[Accendo]

Thank you very much MSIC I understand RAM much more now thanks ^_^. And I'm posting my proposed spec in the hardware channel now so please rip it to shreds and make me cry !