Further my understanding of i7 processors

So I'll unload my knowledge of the aforementioned processors and anyone with clear verifiable information please correct and/or add to what I know. Thanks.

1. Core i7 are all quad core and have HT, thus allowing Windows to see 8 actual cores (does this mean in Task Manager you see 8 graphs?)
2. i7s run at their lower clock speed when running quad core and their higher clock speed when running single core and have the other 3 cores turned off
3. What is Smart Cache? Is it the replacement for L2 cache?
4. What are the benefits of triple channel RAM? Is it just linear scaling, so triple channel is 150% faster than double channel?
5. If only 2 or 3 cores are operating, what is the clock speed? If you say it "adjusts" then isn't that useless, because obviously the higher the better?
6. Because it has 8 virtual cores, does this mean it executes 8 threads simultaneously?
7. A Core 2 Duo T9800 (2.93 GHz, 6 MB, 1067 MHz) and an i7-820m (1.73-3.06 GHz, 8 MB SM, 1067-1033 MHz): For single threaded tasks, is the i7 roughly the same as the C2D (since only 1 core being used, so 2.93 is roughly equal to 3.06)?
8. All i7s are 45 W TDP
9. Currently, there are 720m, 820m, and 920xm (is there a pattern to look for in these numbering?)

Anything else I should know that is essential to the understanding of how i7s work? Thanks!

 

1. Only current i7s are quad cores, there will be i7s in Q1 2010 that are dual cores. For the quad core ones, you will see 8 graphs since it has hyperthreading.

2. Yes.

3. Link? Haven't heard of this Smart Memory.

4. There is no real benefit, but that's the older i7s in desktops. Notebooks and the mainstream desktop i7s are only dual channel.

5. Depends on the Turbo Boost factor (ie. +6 multiplier on 720QM and +8 on 820QM for dual core).

6. Yes, it can execute 8 threads, but not as efficiently as 8 threads from 8 real cores.

7. The i7 has a newer/better architecture, in dual core it would run at 2.80GHz and still be faster than the C2D's 2.93GHz. Maxing out load on a single core supported program, it would definitely run faster than the C2D.

8. No, 920XM is 55W. TDP isn't a good measure since of the architecture change. It now includes the memory controller built-in. Arrandale (Q1 2010 i7s) will have lower TDP and built-in GPU.

9. 920 > 820 > 720 for speed and cost.

 

I don't have specific clock speeds, but for q #5:

1 core active = full turbo boost
2 cores active = less turbo boost
3 cores active = even less turbo turbo boost
4 or more cores active = stock clocks

at 3 cores active, turbo boost really is insignificant ~100Mhz over stock clocks

for q #6:

There are actually 4 physical cores, and 4 virtual cores (when they are all used, they don't refer to them as 8 virtual cores). When 8 threads are needed to be active at any one time, 8 threads will execute simultaneously.

 

I think all 4 cores can also use Turbo Boost (up by one multiplier, yay +133MHz...)

 

I think you are referring to Smart Cache.

Smart Memory is a prefetching technology that "predicts" what instructions are needed next and fills the L2 cache with it.

Smart Cache is cache that can be shared by each core. Basically,info in each core's L2 cache can be utilized by another core. Before, data that each core needed had to be replicated between the respective caches.

Edit:

BTW, Smart Cache is L3.

 

OK guys, I am getting an i7-720m (too bad Dell Canada doesn't have 820m or 920xm) and how do you think it will compare with my older Core 2 Duo T9800?

I play games (Crysis, CoD, NFS, etc.) and go online and do homework. No video editing and no PhotoShop.

I am kinda sad that I can't get 8 MB of Smart Cache (thanks surfasb!) like the 820m and only 6 MB, but would 8 MB pose a great increase over the 6 MB?

And with a socket that takes the 720m, will I be able to upgrade to future i7 quad cores?

 

Currently, the 820QM and 920QM aren't worth their upgrade cost in terms of performance. A 820QM has been shown to outperform a 720QM by maybe 15% in real life performance and it costs more than that percentage lol .

 

I'm not paying for it because it's a replacement, so the faster the better =]

 

Smart cache isn't likely to help your needs a lot. While L3 cache is certainly faster than having to fetch instructions from the main memory, it isn't likely to make a difference with your needs.

 

Well they are faster, but they're not worlds faster that's what I'm trying to say. They're definitely not wort the money faster though that's for sure.

As said, the technology implicated in an i7 is more likely not to provide a significant difference n your uses An SSD or such would provide far more noticeable increases in performance.

 

I don't think you'd notice a difference btw any of those processors in your uses to tell you the truth. A T9800 can run all those tasks just fine, in fact, most of the time it wouldn't even need to run at its full speed, just like the i7s will most likely downclock as well. If there are any better i7 quad cores, it will be in their refresh with maybe another model or two at most, but again, I wouldn't waste my money with any future upgrade.

 

If this was me, about the only difference I would notice is when I'm encoding videos.

 

Agreed, though I can't underscore how big of a difference that is for those of use who encode often. It's night and day.

 

But that's the only time I would notice. Oh one day, Microsoft will add video recognition and I can talk to my laptop like R2D2. And it will automatically create some complex plan to get me out of the pit of Sarlacc.

 

Would there be a difference while doing some 3-D rendering (V-ray, 3DSMax, etc)?

 

Yes.

Nehalem excels in these types of software.

 

1, 2, 4, 6, 8 are answered well so I'll skip those. For the rest...

3. If you are talking about Intel, the correct term is Smart Cache and Smart Memory Access. But really, that's a marketing term, and all it means its improved over previous generation.

5. 2 cores running, 2.4GHz for i7 720QM, 2.8GHz for i7 820QM 3.06GHz for i7 920XM. It isn't useless, because the reason for "adjusting" is to balance power consumption and performance. Also, almost all apps will gain from frequency boost, but not all will gain from core count boost.

7. I think even the slowest, 720QM will be equal/faster than T9800 in single thread. The 2.8GHz in single thread for 720QM will beat T9800. However, single thread performance isn't too important any more than how it will help with multi-core scaling and per core performance. I think you'll be hard pressed to find any apps using less than 2 threads nowadays. Average for new apps is 4 threads, btw.

9. I don't think there's enough info to know if there's any pattern in the numbering. There probably isn't since model numbers are mostly marketing.

 

Thanks to everyone for their input, I really appreciate it! If anyone else has stuff to add please feel free.

 

since your'e getting a free replacement, get a 820QM...

 

Dell Canada doesn't have that for SXPS 16.

 

You have to call them for it. Maybe you can even get a 920XM

 

They offered the 920XM to me for a fee, but it's 55 TDP. I would love to have it, since I value power way more than battery life, however I don't want to melt my laptop or damage its components from a processor that is too hot.

 

Just get a notebook cooler, especially if you're going to be using it at your desk a lot more than carrying it around. I think you would be fine either way.

 

They wouldnt offer a processor if it was to damage the internal components, and they would have to replace it under warranty anyways, so get the best of what they have to offer you.

 

They said that 920XM is for Alienware but he mentioned that I can buy it as a part from Dell and install it myself.