Why is Core i7 920 better than Phenom 2 955

I just want to ask the question above...Core i7 clockspeed is lower, the amount of cache is the same but why does it performs better in most apps? I wonder how, I wonder why...

and it has a slightly higher IPC (instructions per clock)

You don't throw away 10 years worth of effort sorting bugs out of a core unless the previous model was better ... its very hard to start from scratch.

That's why they threw the Pentium 4 away and reworked the Pentium 3 (mobile) to come up with core2. P3 had a higher IPC than P4 ... the pipes were a better design ... or could be improved moreso. The core2 cores are at the heart of the i7 ... some changes of course.

Sorry for the oversimplification ... very crude explanation.

I agree ... for the price it is hard to go past.

But it isn't a better CPU.

phenom II is better value until the i7 price cuts come, and i5 will be just a bit cheaper than i7 is now so AMD doesn't really need to be worried.

I think Intel is making a mistake though by using larrabee as a GPU, if they used it as a CPU they would easily own the market but then I guess the EU would stomp down on them for taking out the competition.

While this is close, its a bit off. Core 2 is actually based off of the Pentium III Coppermine that was a desktop part. What happened was that during the Pentium 4 era is that Intel needed a good mobile offense against AMDs Athlon that was low power and decent performance.

What they did is they wrapped the Pentium III Coppermineinto a mobile package naming it the Pentium M.

What they saw (well the guys in Israel anyways) was that it would run better than a Pentium 4 and clock per clock it whomped it and Athlon like there was no tomorrow.

So they took what they learned from Pentium 4 (lets faces it, the P4s pipeline design was better since it gave the ability to clock higher than others it was just the rest of the arch that had leakage up the arse) and applied it to the Pentium M thus creating Core 2.

Core i7 is Core 2 with a lot of IPC enhancements, a IMC and QPI.

Its not HT. And it was a gimmick but SMT actually does give a nice performance boost. But yes the average user wont see any difference which is why a Pentium Dual Core E2200 is suffice for most average users.

Well that depends on the Core i5s performance. It may be something AMD might worry about.

And Larrabee is a bit different. The design of the processors for it re mainly for GPU applications. Of course they could be using their design based off of Terascale mixed with Core i7s SMT (I think its supposed to be 32 processors with 64 threads and each core is capable of so many shaders) which will be great since Terascale was completely modular.

That means they could have some of the processors be PPUs(Physic Processing Units) and link it with Havoks Physics engine since they now own havok.

And you are right. If they released a CPU like Terascale or Larrabee they would end up monopolizing the market and especially the server market. Terascale was shwon to be able to do the same job as 130 CPUs (it was only 80) and only used 62w @ full load @ 2.5GHz per core. And we all know Intel doesn't want that to happen or they will be broken up again which in the end is bad for us end users.

Well what do you plan on doing? For gaming thats a pretty decent rig right there although for me I would go with the HD4870 2GB but thats cuz I am crazy.

Also, do you know what OS you plan to use? If its XP 2GB of RAM is fine but if its Vista or even Windows 7 4GB+ is always better.

You can't compare Hyperthreading from the P4 era to now. If it made no difference, why does both performance and power consumption increase when it is enabled?

@Psycho, show me some results with them all running at 1600mhz FSB/HT/QPI and 3.2ghz clock speed.

otherwise it will not be a fair test.

The fair test is the price test so you should compare 2 processors with the same or similar price.

Drop the clock speed and slow it down. No kidding?

I'm guessing this was aimed at me but until we fair out the playing field on the CPU's we won't actually know which one is faster clock for clock.

QPI is about 2X's faster then the old 1600FSB. I wouldn't even know where to begin.

How is it fair to slow it down? I don't see the logic. Unless you slow the HyperTransport bus speed as well, then it's fair, because both are being restricted. Restricting one and not the other is not fair. By similar logic you could say "let's disable some of i7's cores and then it will compete evenly with Phenom II"

Actually i7 has less cache compared to Phenom II. Phenom uses exclusive cache, i7 are using inclusive cache. Inclusive cache duplicates data in different cache levels. Exclusive cache don't do that.

http://en.wikipedia.org/wiki/CPU_c [...] _inclusive

hyperthreading is not a gimmick dork! Read up on hyperthreading before you call it a gimmick. Ok, let's make it fair, Hypertransport is a gimmick.

On the other hand, due to inclusive technique, Core i7 also has less cache miss than Phenom II (theoretically speaking). High rate of cache miss means in the case core cannot find the file in its L1 data, it will then seek data in L2, L2s in other cores, and L3s (also segmented among cores), before finally hitting the RAM. This causes outrageously high latencies.

Not really.

K10's latency:


Core i7's latency:


Not only that, the chance of Core i7 having a cache miss (which warrants a read from the RAM) is much lower than Phenom II due to inclusive cache.

does that chart apply to the 955 too?

Yeh, that and a higher HT speed.

22-inch very likely equals 1680 x 1050, right?

2 x HD 4770s have looked really good at that rez - and I was surprised how well they have mostly performed at 19x12, too.

It's a tough call (but) if I were gonna spend $200 today I'd snag an HD 4890 1GB for $200 AR ---->>
http://www.newegg.com/Product/Prod [...] 6814102830

And later on this year when you want to reward yourself (and the price continues to drop) I'd snag another one (so you can play all the upcoming games really fast on that new 50-inch 1080p plasma you get for the holidays - LOL)

blah, blah. tired of seeing these pics....

lmao, good one. Damn i understand being proud of my rig, and it does look nice, but why in every thread?

I am not tired of seeing those pics.

Just stick another 4870 in the box soldier.

Hes got speed stickers on the side panel helps overclock with the magic green AMD lighting meaning the overclocking gnomes are working hard.

Word, Playa.

jealous poor peons without the cash to bling up your rig ... like me.