i5 vs i7 vs Q9450 - key differencies?

[Raistmer]

AFAIK i5 has 4 cores @2.66MHz. Just as my Q9450 has.
What differency with i7? No HT support?
And with Q9450 - different (smaller) cache ?

[Gecko_R7]

AFAIK i5 has 4 cores @2.66MHz. Just as my Q9450 has.
What differency with i7? No HT support?
And with Q9450 - different (smaller) cache ?

No HT on i5 and i5 gives-up some memory bandwidth w/ dual-channel memory vs. tri-channel on i7.

L2 = 256K x4 on i5 & i7, 8MB of L3, though L3 latency substantially higher than L2.
Q9450 has 12 MB L2.

i5 requires new socket 1156.  Also note that I/O bus on i5 is DMI, vs. QPI on i7.
i5 also has integrated PCIe connectivity on die, 16 lanes.  If you connect 2 cards, drops to x8 for each card, or 1 card = all 16 lanes.

i7 920 can be had @ 70 bucks more than i5 & MBs are @ $60 more.
DDR3 memory is still expensive (compared to DDR2).  FIgure $70 for 2x2GB, $100 for 3x2GB
Figure @ $180 MORE to build an i7 920 vs. i5 750

Q9450 will only need dual-channel DDR2 on LGA 775 mobo w/ MBs starting @ $40.00
The 9450 CPU however is pretty expensive @ $300+, can actually get a faster Q9550 for @ $210

Q9550 CPU, MB + 2x2GB DDR2 = @ $315.00
i5 = $370.00
i7 = $550.00

If i were building, I'd choose the Q9550 & put in a GTS250 or HD 4850 for @ $100, depending on project interest.
Would still come in cheaper than i7 w/ better production.
@ $45 more than a i5 build, but way more production.

Q9950 w/ mid level GPU seems to be a nice "sweet-spot" in Value/Performance IMO.

Since you own a 9450 already, the upgrade cost to i5 or i7 means new "everything" exc. power supply & case, lol.
Way cheaper to just add a GPU right now.
Comparatively, i5 performs a little bit better overall, i.e. @ 10% than what you have, i7 @ +30%
Pretty high cost premium for that.

[Raistmer]

Thanks a lot!
It seems i5 step back, not forward...
AFAIK Q9550 has smaller cache than Q9450, but higher freq, so performance will depend from how severe app memory-bound probably...

[Gecko_R7]

Thanks a lot!
It seems i5 step back, not forward...
AFAIK Q9550 has smaller cache than Q9450, but higher freq, so performance will depend from how severe app memory-bound probably...

Q9550 has same 12MB L2 as Q9450, it's just another 1/2 step "up" on the multi, for 2.83 MHz. 

i5 = way bigger profits for Intel re: lower production cost & higher-yields.
Ironically, 1156 Mobo should be cheaper to build than 775 since no seperate NB on MB any more
For now however, consumer doesn't receive any savings since i5 & socket 1156 MB are are "new" w/ limited options. 

However, I bet i5 system prices will become way CHEAP in @ 6-12 months.
Will be a good upgrade option later for a p4 or early core 2 owner who wants to go "quad" for little $.

I'd love to see i5 in a mini-itx board for small form media server/pc. 

[Raistmer]

Q9550 has same 12MB L2 as Q9450, it's just another 1/2 step "up" on the multi, for 2.83 MHz. 

I see. Maybe it mixed in my head with Q9400 or smth alike...     

[Gecko_R7]

Q9550 has same 12MB L2 as Q9450, it's just another 1/2 step "up" on the multi, for 2.83 MHz. 

I see. Maybe it mixed in my head with Q9400 or smth alike...     

Ironically, the 9550 is actually priced @ 125 LESS in U.S. from reputable retailer vs. the 9450
For $209.99 (NewEgg), the 9550 w/ the slightly higher CPU frequency and larger/lower latency L2 "should" be at least as fast as i5 750 on Seti.
i5 does have a bit advantage re: memory x-fers.

[Raistmer]

i5 does have a bit advantage re: memory x-fers.

From DDR3 vs DDR2 memory solely?
Both Q* and i5 MBs will be dual channel, correct?

[Gecko_R7]

i5 does have a bit advantage re: memory x-fers.

From DDR3 vs DDR2 memory solely?
Both Q* and i5 MBs will be dual channel, correct?

Yes, but i5 is Nehalem arch & using IMC whereas Q* uses FSB.

[Jason G]

While the  couple of reviews that I've read were disappointed at the lack of HT in the i5-720 , the combined effect of the DDR3 internal memory controller giving ~50% better memory throughput over core2, and the turbo mode, seemed to bring  most benchmarks on roughly par with QX9770.  Sounds good, though the i7 860 & 870 apparently can outstrip the i7-920 for some things that are more CPU bound, which is way faster.   The same reviews tended to regard the 870 as overpriced, and the 860 as the next 'Sweet spot' processor, because they have HT etc. Part of the reasoning is that the LGA1156 main-boards will still apparently be fairly pricey.

I would hang out for the i7-860 if you can, we're probably going to self critical stride optimised MT FFTs over christmas, a year ahead of the Christmas 2010 schedule. 8 threads versus 4 might be a big deal for that style of programming, which is probably going to become much more common.

I bought a new Noctua cooler for the E8400, and was worried that I'd have to go and buy a new mounting kit for the new socket if I get one of those (or similar)  CPUs & main-boards next year, but it came with an extra little brown box sticky taped to the top, which contained brackets for both the new sockets.

Jason

[MarkJ]

I would hang out for the i7-860 if you can, we're probably going to self critical stride optimised MT FFTs over christmas, a year ahead of the Christmas 2010 schedule. 8 threads versus 4 might be a big deal for that style of programming, which is probably going to become much more common.

Your going to what? I think that translates to "we're going to make a multithreaded app over christmas", but just wanted to clarify.

As for the Noctua coolers. I had a pair of them, threw them out 2 weeks ago as the machine I was building never worked. It even had the bag with all the different variety of mountings (AMD and Intel), although it was purchased before i7's came out. I could have posted them to ya!

Cheers

[Jason G]

Your going to what? I think that translates to "we're going to make a multithreaded app over christmas", but just wanted to clarify.

  Don't be too shocked/excited, It's the natural course of development that the software 'should' change to match the hardware it's running on..  Small advances are made from time to time, and those slowly add up. Sooner or later, multithreaded CPU/GPU hybrids will exist.  MT FFT experimentation over christmas though, doesn't necessarily translate to a working prototype soon thereafter, but at least could identify a few more wrong ways to do things, depending on how good a Christmas Murphy is having.

As for the Noctua coolers. I had a pair of them, threw them out 2 weeks ago as the machine I was building never worked. It even had the bag with all the different variety of mountings (AMD and Intel), although it was purchased before i7's came out. I could have posted them to ya!

LoL, Oh well, postage would likely outweigh the recycling benefit there, literally I reckon. 

Aside, Being my first heat-pipe cooler, I got quite a sense of achievement getting through the complicated installation ... they really thought of everything it seems.  A 20 degree Celsius temp drop, over the big copper Zalman I had from my old p4, was very impressive.  Hopefully that should last through Adelaide summer without issues (this time ... touchwood...).

[zpm]

i'd take i7 and soon to-be I9...

[_heinz]

Hi,
till now I have not for one day repent of the decision to have a Intel D5400XS board with 2 4-core CPUs Xeon E5405 with 2 GHZ. This is real 8 core. Nothing hyperthreaded. I get each cpu for Euro 178,00
The cpu's run easyly 2,4 GHz and are working cool...my 2 cpu fans running still 650rpm under 8*akv8= 100% full load on all 8 cores.
And the board have 4 places for graphic all full 16*
my graka Sapphire HD3870 is passive cooled....temps with 2 collatz or 2 mikyway not higher than ~65 grad celsius
The machine runs now already a year under 100% full load, nothing damaged, technology is proofed...
I trusted Intel, I'm not disappointed. 
Maybe end of next year looking for a new machine....or more powerful grakas...perhaps 4 dualcores
My main problem with the new powerful grakas is the noise and heat, but watercooling parts are still rare and expensive.....
Xeon CPU's are really a good alternative.....

[canapa]

For the moment I've a Q6600@3600
Which differences from a i750 in performance?