Dell Studio 15 with core i5 540M or i7 720QM ???

Hi guys,
i m planning to buy a dell studio 15 laptop (in india). the specs chosen by me are as follows:
4GB (2GBx2) 1333MHz DDR3 SDRAM
500GB 7200RPM SATA Hard Drive
512MB ATI Mobility Radeon HD 4570
6-cell Lithium Ion Primary Battery

i have 2 choices for processor:
Intel® Core™ i7-720QM (1.6GHz, 4 Cores/8 Threads, turbo up to 2.8 GHz, 6MB Cache)
OR
Intel® Core™ i5-540M Processor (2.53GHz, 4 Thread, turbo boost up to 3.06GHz, 3M cache)

core i7 has 1.6ghz processor speed and core i5 has 2.53 ghz speed. also 6mb and 3mb cache difference is there.
How is it going to affect the performance.

I intend to use it as desktop replacement, and i would be running ANSYS and CATIA on it. also a bit of multimedia and entertainment stuff.

the difference in cost will be Rs.7000 (or about US $140).

i am also concerned with battery life (should i go with 9cell battery)and heating issues.

Which one should i buy? pls help i m a novice.

 

If you're doing anything CPU intensive, a quad core will offer a significant advantage. The trade-off is the they use more power, which means less battery life and more heat. You should try figure out which is more important and go from there.

 

yea i'll be doing some heavy cfd simulation (cpu intensive)work on it.
what concerns me is the low processor speed of i7 (1.6ghz).will it affect the performance?

 

For multithreaded applications, the speed will be overcome by the number of threads that the CPU can handle, so don't worry about it.

 

Recent advances in CPU architecture have focused on getting more work done per clock rather than increasing clock frequency. This practice began with Intel's Pentium M processor; a 1.7GHz P-M routinely outperformed Pentium 4 processors running at double the clock speed. The following Core Duo, Core 2 Duo, and Core iX models follow the same philosophy, so don't measure the performance by clock speed. The Core i7 is easily the best consumer CPU out there in terms of performance

 

for the stuff ur doing , i7-720qm will be better but here's a warning... thr 4570 is quite crap so if i were u i'd try getting something with a better GPU... of course if u not gonna play games , 4570 is allright...

 

ya evn i hv heard that 4570 is not that good a gpu but dell doesnt provide me options for that. studio 15 comes with 4570 only. xps 16 comes with 1GB ATI Mobility Radeon HD 4670 but that would overshoot my budget. though i play games but i m not an avid gamer.

 

The main question is, how well parallelized are the specific computations you are doing? Depending on this, a quad-core may or may not offer a big advantage.

You must note that the 1.6GHz base speed of the Core i7-720QM is not all there is to it, because of Turbo Boost. As long as the processor's current, temperature and power do not exceed the specifications, it is capable of operating as a 1.73GHz 4- or 3-core CPU, a 2.4GHz dual-core CPU, or a 2.8GHz single-core CPU. On the other hand, The i5-540M will operate as a 2.8GHz dual-core, or a 3.07GHz single-core CPU.

These numbers aren't directly comparable because of slight architectural differences - in particular the i7 has an on-die memory controller, which is an advantage. However, the overall architecture of the CPUs is nonetheless reasonably similar. Based on the speeds, I'd expect the i7-720QM to be something like 25% faster in a near-perfectly parallelized application, but somewhat slower (10-15%) when using only one or two of its cores. The lower memory latency and higher bandwidth could push things more in the i7-720QM's favour depending on the application, though.

EDIT:
Here's a published ANSYS benchmark. Notably, the Xeon 5365, which is 13% faster in clock speeds than the 5355, gets a 10% boost, while quad-core is around 40% faster than dual-core. This seems pretty good, but in this situation the quad-core was running at the same clock speed as the dual-core - i.e. the boost from quad-core is only 40%, compared to the theoretical maximum of quad-core being twice as fast as dual-core for a perfectly parallelized task. If we're looking at the i7-720QM, it can work as a 2.4GHz dual-core or a 1.73GHz quad-core; since 2.4GHz is 40% faster than 1.73GHz, I would think that the i7-720QM would likely run the benchmark equally well as quad or as dual.

On this basis, I would conclude that the i7-720QM would probably not be faster than the i5-540M for ANSYS. Indeed, since ANSYS doesn't benefit very much from quad-core, and the i7-720QM has lower maximum clocks on dual-core than the i5-540M, it's likely that the i5-540M would actually be faster - unless the on-die memory controller of the 720QM gives it a significant advantage in ANSYS. Unfortunately, I can't judge how much impact memory bandwidth / latency would have on ANSYS.

 

not u and ur theories... OP plz ignore him... he's been proven wrong... just get 720qm

 

I posted a benchmark for ANSYS, which is of far more practical use than the pure guesswork you guys are offering.

 

What are you arguing, exactly?

 

Based on that ANSYS benchmark, I doubt there would be much point going with the i7-720QM for that purpose. Additionally, since the OP said "i am also concerned with battery life (should i go with 9cell battery)and heating issues.", and the i5 is cheaper, I'd go with that.

EDIT: If it's actually the i7 that's cheaper, that's the one to go with, though. The OP didn't make it clear which was the cheaper one.

 

actually i5 was cheaper than i7, now starting from yesterday,dell has modified the customization options, now they offer choice between core i3 350M and i7 720M, dunno why.but i hv now decided to go with i7 even though its more expensive.

 

Yeah, definitely don't go with the i3; the lower clock speed and lack of Turbo Boost hurts them.
Also, do you mean i7-620M or i7-720QM? There's no i7-720M.

 

i7 720qm is slightly faster.

 

it was a typo, its i7-720QM.

 

Well, if it's just i3 or quad-core i7, I'd go with the i7 since it's much more powerful, though you'd lose a little battery life for choosing the i7.

 

yeah i hv ordered now the studio 15 lappy with core i7-720qm and 9 cell battery.

 

I have ordered the same configuration today

I am not into much gaming, but I watch HD content. I had two choices:
Either i7 720QM with ATI Raedon 4570 (comparatively cheaper)
or i5 540M with ATI Raedon 5470 (comparatively costly).

I choose i7 720QM with ATI Raedon 4570.

 

The 4570 and 5470 are close in performance, so that was probably a good choice, considering it was cheaper.

 

Oh, thanks for supporting me

 

Both ATI HD 4570 and HD 5470 supports DXVA (Hardware decoding of H.264) so 1080p HD content should play fine.
And as of ATI Catalyst 10.3 driver suite should support notebook gpus, so if the DXVA shows up buggy you can just upgrade the graphics driver.

 

The CPU is powerful enough for 1080p even without hardware acceleration anyway, so there's nothing to worry about there.

 

Are you sure? I've read some reviews of the Intel HD graphics that show it as strong with 720p, but jumpy with 1080p.

 

Intel HD graphics still counts as hardware acceleration, no?
If you can use DXVA you're better off that way, but with that CPU it's not a necessity.

 

Another relief to my soul
There are some great guys around here.

 

Hey there Wecaz.

Did you get an order with the i5 540 and the ATI Raedon 5470?...

Are you ordering from the US or the UK? My order just got a month added to the delivery date and I am a bit annoyed, so I am going to phone sales and try and pay for an upgrade. As at the moment I am schedualed to get it 2 months after ordering it!? Great, getting a laptop which is already 2 months obselete..

Did you go through the internet or phone to get that setup?

Any info would be great.

 

hey can anybody tell whether 90 WT AC adapter is suffucient with i7-720qm n 9 battery o one should use 130 wt AC adapter ? plz suggest !
thanking you !

 

i suggest a 130W one of same side.. 90W is a little too little with i7-720qm 45W + 25W GPU+ screen etc..