This has confused me ever since the beginning of time. I always thought that a higher Ghz on a processor meant that it was better. So a 3.4 Ghz Processor is better than a 3.0 Ghz Processor. But then I see times where the computers with lower processors are more expensive than the ones with the higher processors. And then there is the whole AMD thing, that you see on ads, that doesn't even say the Ghz on it but instead some name like Althlon, Celerlon, etc. How do we know how good those processors are?
The same thing applies to RAM. I sometimes see a 512MB Ram stick go for more than a 1GB ram stick. Why is that?
The reason I ask is because I want to get me a new computer and I want to buy the best one I can get for the money I have. So knowing what kind or RAM is better or worse and what kind of processors are better would help tons.
Speed in Ghz measures how many cycles per second the CPU gets, so a 3.0 GHz CPU gets 1 billion more cycles each second than a 2.0 GHz CPU. What this doesn't tell you is how many cycles each CPU task (calculations, memory access, etc) takes -- while an older CPU might have taken 20 cycles for an operation, it's possible that a newer CPU can do the same task in 2 or 3. This can really add up, making a new ~2GHz CPU (like a Core 2 Duo) own an older 3GHz CPU (like a Pentium 4). This is the general trend in CPUs, where speed is staying the same but efficiency is getting a lot better. There's also the numbers of cores to think about as well -- all of the newer CPUs actually have a couple processors built into them instead of one.
As far as the RAM goes, it all depends on the type of RAM and the demand. That, and there is a lot of RAM that sells for horrible prices. Right now a couple of 1 GB sticks of DDR2 800MHz for desktop PC is priced well at around $50.
Now for the new computer -- post your desired price here and people will be glad to give you suggestions on the best system for the money.
Message edited by williamfontaine on 11-04-2007 at 06:58:45 PM
Pentium 1 1.1
Pentium MMX 1.2
Pentium 3 1.9
Pentium 4 (Wil) 1.5
Pentium 4 (Nor) 1.6
Pentium 4 (Pre) 1.8
Pentium 4 (Gal) 1.9
Pentium D 2
Pentium M 2.5
Core 2 3
K6 II 1.1
K6 III 1.3
Athlon B 1.9
Athlon C 1.9
Athlon XP 2
Athlon 64 2.3
Athlon 64 X2 2.5
Via C3 0.85
Via C7 0.9
This chart shows the "instructions per clock". The higher the number, the better (i.e. a 3 Ghz Pentium D will equal a 2 Ghz Core 2 Duo - because the Core 2 can do more operations in one clock cycle than a Pentium D). It kinda gives you an "apples to apples" comparison of various generations of processors.
I agree with williamfontaine, post your budget and needs and we can steer you in the right direction.
The simple way of seeing it. Think of the CPU being a shovel. So we are digging in the ground.
The older CPU with High Ghz speeds:
Code :
-----------
|------------------------I
-----------
And todays CPU with lower Ghz:
Code :
-----------------------
|
|------------------------------------------I
|
-----------------------
So... basically you can dig more dirt with todays CPU then the older ones, even at a slower speed. But then the Ghz matter when you have the same type of shovel.
As far as the ram goes, it depends on what system you looking at, that will effect the overall performance of the system.
They don't tell you what the motherboard is mainly because computers sold in the store just use run-of-the-mill el-cheapo motherboards that don't give you very much control over CPU/RAM settings and other stuff. Big places like Dell might use motherboards specially built for them (not sure though). The model of motherboard really only becomes a factor when you're building your own system and deciding what options (and overclockability) that you want.
Well what motherboard it is would be important to me if I decided to upgrade it. Most computers don't come with full memory slots, and I could definitely see myself buying a 1GB RAM computer and upgrading it to 2GB. But doesn't the motherboard control what kind of ram it can run and depending on how many memory slots are on the motherboard, it can control the amount of ram you can get in it.
Also, wouldn't the motherboard type affect the type of video card you can upgrade to?
So, like I wonder why they don't post the motherboard type. I can understand the logic that the motherboard is lame, but then how do you get a good computer (buying, not building) if they all come with bad motherboards?
Matt, There is a lot more to Processor's and Ram then just there size/speed.
First, a processor has 1.GHZ - already been explained
2.What kind of socket it is, this refers to the number of pins it uses to connect to the motherboard.
3.Number of Cores - newer processors have 2 or even 4 cores compared to 1
4.Cache - Cache is a small amount of memory in the KB size, like 512 1MB 2MB 4MB or even 8MB that stores CPU instructions, this can have a large effect on performance.
5.Build Architecture this refers to the size and method of creating the processor, older AMD's are made on a 90nm process while Core 2's are 65nm (I believe, sorry if i'm off) and soon to be 45nm. This effects the efficiency of the processor, its heat dissipation(how hot it runs) and its overclockability.
6. Front Side Bus- or HTT on AMD processors is a small bus that carries information from the processor to the northbridge on your motherboard.
it also greatly affects the speed of your processor and ram.
Intel can have front side buses from 200-266-300-400 if overclocking
AMD K9 is generally around 200.
7.Sudo 64bit- this means if a processor can fake 64bit even though its only 32bit, for vista and 64bit applications, although many processors are 64bit already.
8.The other thing that i can think of that separates processors is the architecture of their built in programs, Intel has Wide Dynamic Execution, Smart Memory Access,Advanced Smart Cache,Advanced Digital Media Boost,Virtualization Technology.
AMD has Cool and Quiet and its HyperTransport.
9.Also a big affect on performance is whether the memory controller in the system in on die or not, which means if the memory controller is on the mobo or the processor. Before only AMD had it on die, but Core 2 now has it on die i believe or soon will.
Ram is affected by a few things as well.
1.Theres Size obiviously, 512MB,1gig,2gig,4gig
2.Speed DDR-400 DDR2-566 DDR2-667 DDR2-800 DDR2-1066 DDR3-1333
3.What kind of ram it is, DDR= Double Data Rate DDR2=Double Data Rate 2,capable of better speeds and less voltage, and DDR3=Double Data Rate 3, which is like DDR2 but even more so.
4.Timings, Timings in ram are huge, they're very similar to the cycles of a CPU in that it shows how long it takes for the ram to take in and store information, CLS 5-5-5-5-17 might be a typical rate for DDR2 ram, although there are lower ones available for money, thats probably why a peice of 512 can be worth more than a 1 gig peice.
5.Dual Channel, This refers to the ability of the ram to use the Ram slots on a motherboard more like a highway in that it has 1 channel for outgoing and another one for incoming. This has a huge effect on performance in that 1 gig dual channel will out perform 1.5gigs or even 2 gigs single channel.
This is my understanding of Processors and Ram, so if i'm wrong in any way feel free to correct me
Message edited by meowkitty77 on 11-04-2007 at 08:20:38 PM
Well they're not necessarily bad if you don't want to control all the details. If the computer you're buying comes with a PCI-E video card slot then all new graphics cards will work in it (well, as long as there's room in the case and the power supply can handle it). As long as the motherboard has a couple of DDR2 slots (which I would assume most do) then you can put in a couple of 1GB RAM sticks later to upgrade to 2GB.
If you want to go the route of buying a pre-made PC and would like to make sure it's pretty good, you can post a price range for suggestions. Or, whenever you find something you think looks good, post it on here and see if anyone has found something better. I happened to get a Dell in 2004 (even though I had built my own for the previous 5 years) because I found a fantastic deal where they threw in a 19" LCD monitor for free, and I couldn't match the price. It didn't have everything I wanted but I've been able to upgrade a few parts over the last couple of years.
The next PC I get, however, is going to be one I build exactly how I want it
The main reason I ask is because I plan on buying a computer this Thanksgiving (Black Friday), and the prices are really good, but I want to make sure the computers are good too. The more I know about how to tell how good the pieces are, the better I can be on choosing what computer to buy.
Well to break it down for you, different processors can accomplish different amount of tasks per cycle. Like lets say, a core 2 duo processor, can do more instructions per cycle than a pentium 4 processor, which makes it faster even though it's at a lower speed.
With ram, not only does size matter, but at what speed the ram runs at. For example, if you look at the ddr2 models of ram, they run at higher speeds than ddr. The fastest speed for ddr memory is ddr-400, which runs at 200 mhz frequency (Just divide it by 2 to get the frequency). The faster the memory, generally, the more expensive it is. Ddr memory works is 184 pin, and ddr2 is 240 pin, which means that each is compatible in different motherboards. The new motherboards support ddr2, and older ones support ddr.
That's not necessarily what I'm saying. Since he's probably buying a pre-built machine, then he most likely will not be able to overclock it. So he can't go wrong with either a core 2 duo or an Athlon x2 processor.
Ok, since you're buying a brand-new off-the-shelf computer I'll let you in on what you'll see:
You will NOT see AGP graphics or DDR memory. They will definitely have PCIe graphics slots and DDR2 memory. No need to tell you about old technology (since you definitely won't be buying it).
Will will have a choice of AMD Athlon X2 (and maybe Athlon 64 - not advisable) or Intel Core 2 (Duo, Quad and Extreme), Pentium Dual-Core (an entry-level Core 2 Duo), and Celeron D (very few, which are old and not advisable to purchase).
With ram you'll want to purchase either 2GB or 1GB (one stick of 1GB, not 2 sticks of 512MB). Memory prices are incredibly low right now so I would advise you to get 2GB, but if you're planning on upgrading instead (buying 1GB initially), make sure both ram slots are not filled. You'll want either DDR2-667 or DDR2-800 speed. Corsair, OCZ, Adata, Kingston and Patriot are respected names in ram.
Please reply to this thread with your intended use and we can advise you to the specifications you might want to look at in your future computer.
A very simple way of answering the original question
is to compare a basic 8-bit processor, with a basic 16-bit
processor, then with a basic 32-bit processor.
Let's take a fundamental instruction like LDA
(Load the A Register with the contents of
some address). Its companion is STA (Store the contents of the A register at some address).
In many high-level languages, we have numerous
statements just like this:
I = I + 1
The logical meaning here is to add one (1) to the
current value of the variable "I", as happens
when we are counting the number of occurrences
of "something".
Here's how that high-level statement looks
in assembly language:
LDA I
A1A STA I
Meaning:
(1) load the A register with the contents of the
memory address assigned the name "I";
(2) add 1 to the current contents of the A register;
(3) now, store the contents of the A register
at the memory address assigned the name "I".
If there are only 8 "wires" connecting memory and the CPU,
then that CPU must fetch 8 bits a total of 4 times from memory
if the variable "I" stores 32 binary digits. Call that "four cycles".
If there are only 16 "wires" connecting memory and the CPU,
then that CPU must fetch 16 bits a total of 2 times from memory
if the variable "I" stores 32 binary digits. Call that "two cycles".
If there are a full 32 "wires" connecting memory and the CPU,
then that CPU can fetch all 32 bits all at once from memory
if the variable "I" stores 32 binary digits. Call that "one cycle".
If there are a full 64 "wires" connecting memory and the CPU,
then that CPU can fetch 64 bits all at once from memory,
and store the second half in a high-speed "cache" that
makes it unnecessary for the machine to go "all the way"
out to RAM to fetch the address right next to "I".
This is actually a gross over-simplification, because the
meaning of the instruction "LDA" in machine language
very probably requries numerous different discrete microcode
steps, each of which requires a separate machine cycle.
For example, the variable "I" is a relatively high-level concept
which requires the machine to translate that logical address
into a real, physical memory address.
A logical address is usually some numerical offset from a
base or starting address that is also a variable, in fact,
because modern computers exploit what's called "relocatable code".
Moreover, the logical-to-physical address translation
may require the machine to enter a long sequence
to fetch a "page" of 512 bytes which have been temporarily written to a "swap" or "paging" area
on the hard drive.
Thus, even a very simple instruction like "LDA I"
can literally involve hundreds of discrete machine steps.
The oscillation rate of a CPU tells only part of the story
of its ability to do useful work. All other things being equal,
a 32-bit CPU should be 4 times more powerful than
an 8-bit CPU, if both are oscillating at the same frequency.
Once again, however, this is an over-simplification, because 32-bit CPUs are generally much newer, historically speaking, and they have many more
low-level instructions than much older 8-bit CPUs.
The simplicity ends as soon as you discover that
modern CPUs are designed to do what's called Complex
Instruction Set Computing ("CISC" ), as opposed
to Reduced Instruction Set Computing ("RISC" ).
And, as a general rule, the more complex a given instruction set, the more a computer can accomplish during a given number of
clock cycles.
The more "reduced" a given instruction set,
the faster a computer clock must cycle in order
to accomplish the same amount of work
as a CISC machine.
What distinguishes the Core 2 architecture
from the obsolete Netburst architecture is that the latter instruction set was just
not as efficient at doing a given amount of work as the newer Core 2 instruction set.
Necessity was the mother of invention (again),
because the Netburst architecture hit a physical
"wall" due to the excess heat that was being
generated by ever increasing CPU clock oscillation
rates. Netburst simply could not be made to
cycle much over 4 GHz without very special cooling
approaching "cryogenics".
The latter is also true of the Core 2 architecture,
but that "wall" will be reached at a much higher
clock oscillation rate.
The latter phenomena were THE MAIN reasons
why Intel and AMD decided to embark on a multi-core philosophy, e.g. "Core 2 Duo"
across the board (second core architecture,
dual-cores per CPU) and "Core 2 Quad"
(second core architecture, quad-cores per CPU).
The rest is history e.g. Intel will soon retire
all single-core CPUs in early 2008: all Intel CPUs
from that point forward will each have multiple cores.
So, in conclusion, please let us know what kinds of "work"
you plan to do with any computer you might buy, and
how fast do you want your computer to perform that work.
Then we'll be able to give much better answers to your questions.
Honestly, if all you want to do is to surf the Internet,
do a little word processing, and watch video stored on DVDs,
a single core Intel CPU with the Core 2 architecture
oscillating at ~2 GHz will be more than enough, e.g.
Celeron 440.
As a first-order approximation, one clock cycle per second equals one binary digit ("bit" ) per second.
At 2 billion bits per second, even that lowly Celeron 440
is theoretically capable of keeping 2,000 DSL wires busy,
if each DSL wire moves data at 1 million bits per second!
THAT'S HOW VERY FAST MODERN CPUs HAVE BECOME!!
That's also why it's very easy to OVER-BUY a modern dual-core CPU:
for routine things like surfing the Net and word processing,
such a modern CPU will spend upwards of 90% of its time IDLING
i.e. doing nothing except waiting for more work to perform.
So we just gave the short and to the point that he wanted and then Mr. Mitchell went waaaay overboard (not that it's good, but c'mon!). I'd go by what KyleSTL said on the previous post, for the short and skinny version. Would you please let us know how much your going to spend on this proposed computer? It's been asked about 4 times and you haven't answered it. If you spending $2,000 than we can offer some tips. If your spending $500, than we would definately have to give you other options. So PLEASE let us know your budget!!
