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in the old days you had one core on a chip. you had motherboards that had 2 sockets for 2 chips for multipocessing. Now theire is a dual core. that means 2 cores on 1 chip. (so a motherboard wit 2 sockest wit 2 chips that are dual core has 4 cores)

on DDR

Seem intel will switch to DDR3 in the middle of 2007. Theire s oalso talk that AMD might jump from DDR2 straigt to XDR. <img src="/ubbthreads/images/graemlins/up.gif" alt="" />

Yes, Morbo wrote it quite good, if I understood it correctly.

Old-fashioned it was always one core = one chip. Or rather : one core ON one chip.
Now, things are that you can have two cores on one chip.

Now, how do I exactly define "core" ... ? <img src="/ubbthreads/images/graemlins/think.gif" alt="" />

think of it like this:

a CPU can only do certain instructions (add, subtract, multiply,...)

Now if an instruction is loaded into the CPU it is put in a queue since a CPU can do only one thing at a time. (actually there are sevreal queues and waiting strategies for process switching) look at the 1st PP slides

now one core means that you can do only one thing at a time. (because the CPU is so fast it looks like you are running and doing multiple things at a time)

If you have a dual core processor it can do 2 things at a time. But there are problems that can come with it.

original program:
add 1 to i
add 1 to i
write to memory

CORE 1
0:00:00 add 1 to i
0:00:01 write to memory

CORE 2
0:00:02 add 1 to i

Now assume that core 2 was buzy with other stuff and that te instruction of add 1 to i was delayed. Core one will write 1 to the memory whikle it had to be 2. thats why theire needs to be a whole lot of locking mechanisms, algoritmes to prevent this from happening.

Now it is mostly used to run processes that have noting to do with each other on the cores.

So, basiclly dual cores means two processors in one?

By the way, in one of the books I read (the one I understood <img src="/ubbthreads/images/graemlins/rolleyes.gif" alt="" />) they called that queue 'pipelines'. In these pipelines they reduced big CISC-instructions into small RISC-instructions. But this basiclly mean you can't eve do one instruction/clockcycle, you have to use 20 (or something like that in a Pentium4. AMD's are shorter, and that's why they can run on much lower clockfrequences and still be as effective as Pentium4). But dual-core means you can run two CISC-instructions at the same time, and so basiclly double the proccessor's effectiviness?

And I still only have letters on the DDR-variations <img src="/ubbthreads/images/graemlins/suspicion.gif" alt="" />.

Was planning on writeing a part about either computer theory, or a preview on what my site will look like tomorrow.

Übereil

Yep you got it. dual core meens 2 CPU's on one chip.

from wiki

DDR:

DDR SDRAM or double-data-rate synchronous dynamic random access memory is a type of memory integrated circuit used in computers. It achieves greater bandwidth than ordinary SDRAM by transferring data on both the rising and falling edges of the clock signal (double pumped). This effectively nearly doubles the transfer rate without increasing the frequency of the front side bus. Thus a 100 MHz DDR system has an effective clock rate of 200 MHz when compared to equivalent SDR SDRAM, the “SDR” being a retrospective designation.

With data being transferred 8 bytes at a time DDR RAM gives a transfer rate of (memory bus clock rate) × 2 (for dual rate) × 8 (number of bytes transferred). Thus with a bus frequency of 100 MHz, DDR-SDRAM gives a max transfer rate of 1600 MB/s.

JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.

DDR is slowly being replaced by DDR-2, which has some modifications to allow higher clock frequency, but operates on the same principle as DDR. Competing with DDR-2 will be Rambus XDR-DRAM. It is expected that DDR-2 will become the standard, since QDR (Quad Data Rate) is too complex to implement, while XDR is lacking support.

DDR Prefetch buffer width is 2 bit, DDR-2 uses 4 bit.

Memory manufacturers have stated that it is impractical to mass-produce DDR-1 memory with effective clock rates in excess of 400 MHz. DDR-2 picks up where DDR-1 leaves off, and is available at clock rates of 400 MHz and higher.

RDRAM is an alternative to DDR SDRAM, but most manufacturers have dropped support from their chipsets.

DDR2:
The advantage of DDR2 over DDR SDRAM is the ability for much higher clock speeds, due to design improvements. With a clock frequency of 100 MHz, "SDR-SDRAM" will transfer data on every rising edge of the clock pulse, thus achieving an effective 100 MHz data transfer rate. Unlike SDR, both DDR and DDR2 are double pumped; they transfer data on the rising and falling edge of the clock, at points of 0.0 V and 2.5 V (1.8 V for DDR2), achieving an effective rate of 200 MHz (and a theoretical bandwidth of 1.6 GBps) with the same clock frequency. DDR2's clock frequency is further boosted by electrical interface improvements, on-die termination, prefetch buffers and off-chip drivers. However, latency is greatly increased as a trade-off. DDR2 Prefetch buffer is 4 bits wide, whereas DDR is 2 bits wide & DDR3 is 8 bits wide.

Power savings are achieved primarily due to an improved manufacture process, resulting in a drop in operating voltage (1.8 V compared to DDR's 2.5 V). The lower memory clock frequency could also help — DDR2 can use a real clock frequency 1/2 that of SDRAM whilst maintaining the same bandwidth).

DDR2 was introduced at two initial speeds- 200 MHz (referred to as PC2-3200) and 266 MHz (PC2-4200). Both perform worse than their DDR equivalents since heightened latency makes total access times twice as long in the worst case scenario. However, DDR won't officially be introduced at any speeds above 266 MHz (533 MHz effective). DDR-533, and even DDR-600 SDRAM exists, but JEDEC has stated that they won't be standardized. These modules are mostly manufacturer optimizations of highest-yielding chips, drawing significantly more power than slower-clocked modules, and usually don't offer much, if any, higher real-world performance.

Currently, at least Intel supports DDR2 in their 9xx chipsets. AMD also has plans to add DDR2 support into their AMD64 processors (all of which have on-die memory controllers) during 2006.

DDR2 SDRAM DIMMs have 240 pins (as opposed to 184 pins on DDR DIMMs, and 168 pins on SDRAM DIMMs).

DDR3:

DDR III, likely to be called DDR III SDRAM (Double Data Rate Three Synchronous Dynamic Random Access Memory), is the name of the new DDR memory standard that is being developed as the successor to DDR2 SDRAM.

The memory comes with a promise of a power consumption reduction of 40% compared to current commercial DDR2 modules, due to DDR III's 90 nanometer fabrication technology, allowing for lower operating currents and voltages (1.5V, compared to DDR2's 1.8V or DDR's 2.5V). "Dual-gate" transistors will be used to reduce leakage current.

DDR3 Prefetch Buffer width is 8 bit, whereas DDR2 is 4 bit, and DDR is 2 bit.

Theoretically, these modules could transfer data at the effective clockrate of 400-800 MHz (for a bandwidth of 800-1600 Mb/s), compared to DDR2's current range of 200-533 MHz (400-1066 Mb/s) or DDR's range of 100-300 MHz (200-600 Mb/s). To date, such bandwidth requirements have been mainly on the graphics market, where vast transfer of information between framebuffers is required.

Prototypes were announced in early 2005, while DDR3 specification is expected to be publicly available in mid 2006. Supposedly, Intel has preliminarily announced that they expect to be able to offer support for it near the end of 2007. AMD's roadmap indicates their own adoption of DDR3 to come in 2008.

The GDDR3 memory, with a familiar name but an entirely dissimilar technology, has been in use for several years in high-end graphic cards such as ones from NVIDIA or ATI, and as main system memory on the Xbox 360. It is sometimes incorrectly referred to as "DDR3".

XDR:

XDR DRAM is a high performance RAM Interface like SDR-SDRAM and DDR-SDRAM. The XDR solution was engineered to be effective in small high-bandwidth consumer systems as well as in high-performance main memory applications. Rambus owns the technology. XDR is the official choice by Sony for the PlayStation 3 console.

rambus:

The first PC motherboards with support for RDRAM debuted in 1999. They supported PC800 RDRAM, which operated at 800 MHz and delivered 1600 MB/s of bandwidth over a 16 bit bus using a 184 pin RIMM form factor. This was significantly faster than the previous standard, PC133 SDRAM, which operated at 133 Mhz and delivered 1066 MB/s of bandwidth over a 64 bit bus using a 168 pin DIMM form factor.

Some downsides of RDRAM technology, however, included significantly increased latency, heat output, manufacturing complexity, and cost. PC800 RDRAM operated with a latency of 45ns, compared to only 7.5ns for PC133 SDRAM. RDRAM memory chips also put out significantly more heat than SDRAM chips, necessitating heatsinks on all RIMM devices. RDRAM also includes a memory controller on each memory chip, significantly increasing manufacturing complexity compared to SDRAM, which used a single memory controller located on the northbridge chipset. RDRAM was also two to three times the price of PC133 SDRAM due to a combination of high manufacturing costs and high license fees. DDR SDRAM, introduced in 2000, operated at an effective clockspeed of 266 MHz and delivered 2100 MB/s over a 64-bit bus using a 184 pin DIMM form factor.

With the introduction of the i850 chipset, Intel added support for dual-channel PC800 RDRAM, doubling bandwidth to 3200 MB/s by increasing the bus width to 32 bit. This was followed in 2002 by the i850E chipset, which introduced PC1066 RDRAM, increasing total dual-channel bandwidth to 4200 MB/s. Also in 2002, Intel released the E7205 Granitebay chipset, which introduced dual-channel DDR support for a total bandwidth of 4200 MB/s, but at a much lower latency than competing RDRAM. In 2003, Intel released the i875P chipset, and along with it dual-channel DDR400. With a total bandwidth of 6400 MB/s, it marked the end of RDRAM as a technology with competitive performance.

Thank you <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />. I thought the bandwidth was higher on the DDR-tecniques though <img src="/ubbthreads/images/graemlins/suspicion.gif" alt="" />.

But anyway, it seems that DDR2 (and 3) is optimized verisions of DDR. Sais it all, without saying anything more really <img src="/ubbthreads/images/graemlins/rolleyes.gif" alt="" />.

By the way, is dual coreing something they use in the proccessors you can buy today, or is it something for the next generation of processors? And how was it, does AMD support DDR2 yet?

Oh, and if anyone can give me a good source on AMD Authon vs Intel Pentium 4, I would appreshiate it <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />.

Übereil

I think AMD is better, except for Sempron wich i have....

Amd is currently better since they had planned ahead. Intel got in real problems when they couldn't speed up their processors and had to do a quickee daul core CPU (and it shows).

Intel has a severe problem with heat and current-hungry processors. AMD is a bit better, but in general all modern processors have problems with heat and are *very* hungry. Except mobile processors, of course, which unfortunately don't come in desktop PCs.

This means that you'll need a *really* good cooler nowadays.

Don't lump them all together !

PowerPC chips - mostly used in Apple / Mac computers - produce less heat and use less power than any AMD or Intel chip. PowerPC doesn't need a active cooling - passive cooling is enough !

No mac users here ?

Not in a thread about IBM compartible PC's <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />.

Übereil

hm now tell me they are gonna put intel inside mac's why doncha <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />

Well, PowerPCs are not the same as "Desktop PCs", imho. MACs are a different breed, imho. Although they *can* be used as Desktop PCs.

No, I primarily meant Intel/AMD.

Besides, when talking IBM compartible PC's, you can choose between Intel and AMD. There are no others anymore.

Übereil

Ube, if u're talking about lightweight PC (as in weight itself & also application relatively), there's always the VIA's EPIA CL 10000(1GHz C3 processor) & the slightly lower CLE 6000 (fanless 600MHz Eden processor). nrmally these processors come attached/soldered to the motherboards. for more info on these mini-itx, check out Mini-ITX website. u can always check out the links on the right-hand side, particularly mini-itx 101 & history for clarity in the technology.

what is the criteria of this PC building project that u have to do, Ube? without requirement & criteria, u can always build even the oldest PC that can run Win98SE & OpenOffice for most cost-effective office PC. that can be a Celeron 366MHz with 128MB/256MB SDRAM with mobo that comes with many built-in features. now that's CHEAP. as in EL-CHEAPO. <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />

before i go on, best that i clear up what in need to say; first state the reason or requirement why u need to build the computer. yep, the most important thing about PC building is NEED. not specs. NEED. why?

NEED will determine your budget, the processing power & needs, short/medium/long term need or use, priority etc. without NEED, your PC building has no clear purpose (other than to pass up something to the teacher).

so how many kinds of NEED there is? there's need for office PC (stable, no need to be speedy, enough RAM to handle large files, CD/DVD writer for backup purpose, small physical size for casing so it's space saving, large monitor size for document editting especially spreadsheet preferably LCD since it has less flicker), gaming PC (tons of websites out there that can help u out in this), workstation (for more specialised use such as programming, IDE etc) & on & on & on.

i believe your project only need to concentrate on one such need so u can decide which to do then dive into it.

hope that helps.

If I'd buy a computer, what would it look like? That's sort of the goal. I've planned to built a PC that is as good AND priceworth as possible. One AMD, one Intel. And since I like to play games <img src="/ubbthreads/images/graemlins/rolleyes.gif" alt="" />...

Übereil

Does a local library carry Maximum PC? The September issue for last year had a 'dream machine' feature where they built the best possible computer they could come up with, though at a totally unreasonable price point (almost US$13k). The following month they put together a budget computer (at a tenth the cost) for the best performance to price ratio. The January issue had comparisons of various components: AMD vs Intel CPUs, the best high end / mid range / budget video cards, etc. This month (which I have not gotten to yet) has a test/review of the latest dual core CPUs from AMD and Intel. These articles, and various other reviews, could give you some ideas for your own builds.

A couple other things I didn't notice answered above;
AMD will be introducing DDR2 support in an upcoming CPU, which should be out in the second half of this year (Chips In 2006: A CPU Roadmap).

PATA = parallel ATA = the standard old ribbon cables that are being replaced by SATA. It has only become necessary to start specifying the parallel part of PATA since the introduction of SATA, to avoid possible confusion.

OK, thank you. I'll check into Maximum on Monday. Had today off due to the yearly Nighttime indoorbandy tornament yesterday.

Übereil

Currentlly working on RAM-memories, and I have a few questions:

What's the pros/cons of haveing two 512 MB over haveing one 1024. We're talking DDR of the same DDR-verision. And of the same developer.

Does size (the thing mesured in MB) have anything to do with bandwidth, or is bandwidth just dependent on clockfrequence (sp?)?

Besides, if anyone happens to have a great AMD vs Intel link, I wouldn't mind if you posted it <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />. Am going to google the subject tomorrow.

Übereil

it's hard to have dual channel mode with 1 1024MB module.