the Black Monarch wrote:you: yes, like I said fifty billion times before, clock speeds are just as important as efficiency. But I like efficiency better than high clock speeds.
me: But you still haven't explained WHY!!! AAAAURGH!!! *head explodes*
you: okay, the real reason I hate the Intel is because they were smart enough to make a chip that was just as fast as ours but looked a lot faster, and we wish we'd thought of that first.
Argh! Let the topic die!!!! Final response...I swear.
Why do I prefer a more efficient solution....because I've been taught to design that way. Given it's not exactly the best with respect to money since it wouldn't adhere to the speed = performance misconception. In school we are taught to design the most efficient designs and the more elegant solutions. That's just how it works...
Oh and it's not best to continually take cheap shots when you're trying to get info.
the Black Monarch wrote:According to PCmech.com, the PIII executes 5 instructions per clock cycle, and the P4 executes 6. So how the hell could a PIII at a given clock speed outperform a P4 at the same clock speed? you said yourself that performance = etc. etc....
First of all, I question your source, but upon going to the website I found
this article which seems to quite contradict what it also supposedly says. Let me quote the line that is of importance:
"Along comes the Pentium 4, equipped with an instruction pipeline that is twice as long as it's predecessor, the Pentium iii, 20 stages to be exact. For a 1.5GHz P4, which is what Intel plans on releasing it at, the pipeline will take (assuming one instruction per stage per clock cycle.) the P4 will still pump out 1 instruction per pipeline per clock cycle, but
each individual instruction will take 1.333*10-8 seconds to get out of the pipeline. That's 0.333*10-8 seconds longer than it's predecessor, which isn't good.
But, because the P4 will still pump out one instruction per clock cycle, which is still good.
It will just take longer to do individual instructions.
In processor heavy benchmarks, such as 3D games, the Pentium 4 at 1.4GHz is actually shown to be lesser than or equal to the speed of the Pentium !!!. Please be aware that the Pentium 4 tested was a pre-release sample, and meant only to improve the final product by finding faults before they go on sale, just like Beta Software.
Before I go any further chastising the Pentium 4 for being mentally slow, I must say there are a few advantages to having a longer member...err...pipeline. A longer pipeline gives the chip the ability to be ramped up to higher clock speeds. This helps to offset the obvious disadvantage of a longer pipeline at the same clock speed."
Now let me say that the numbers are VERY incorrect in that the P4 DOES NOT churn out one instruction per clock, however his statements about being "mentally slow" ARE correct. As he also states, they did this so they could bump up the frequency.
Now of course they ASSUME one instruction per clock, but even if it were 6 vs. 5 (which I am not sure if it's true), it's obvious the 5 would come out quicker due to an efficient core which is what I've been saying. Now again, if you pump up the clock, you can close this efficiency gap as earlier stated.
Here is a fairly technical article that goes through it. Given 99% of it is not valid with respect to this argument (I'm not saying the info isn't correct, just saying most of it is not related0 so I'll point out a few quotes:
"and anyone who was paying attention
during that time learned at least one, major lesson: clock speed sells. Intel was definitely paying attention, and as the Willamette team labored away in Hillsboro, Oregon they kept MHz foremost in their minds. This singular focus is evident in everything from Intel's Pentium 4 promotional and technical literature down to the very last detail of the processor's design. "
"This article will examine the tradeoffs and design decisions that the P4's architects made in their effort to build a MHz monster"
"
As we'll see, the Pentium 4 makes quite a few sacrifices for clock speed, and although Intel tries to spin it differently, an extraordinarily deep pipeline is one of those sacrifices. "
"The P4's long pipeline means that bubbles take a long time to propagate off the CPU, so a single bubble results in a lot of wasted cycles...So a single bubble in the P4's 20 stage pipeline wastes at least 20 clock cycles (more if it's a bubble in one of the longer FPU pipelines),...20 clock cycles is a lot of wasted work, and even if the P4's clock is running twice as fast as the G4e's it still takes a larger performance hit for each pipeline bubble than the shorter machine."
Now I know that's pretty technical, but all I'm getting at is that the architecture IS more inefficient regardless of what you've read. At the same time, it runs quite fast as previously stated. I will of course that QUITE a bit of the article is unrelated (and hence the quotes instead of reading). Also I will state that later on it does talk about how the P4 handles some of these deficiencies (like the scheduler). I will admit that just in case of a rebutal (since I'm trying to kill the thread...tired of writing so much

).
I don't really have much more to say since well...it's fairly well-accepted fact that the P3 is greater in efficiency than the P4. Also, Ars Technica is a fairly well-respected site with regards to this stuff.