P8700 or T9550

Is it worth the extra $125?..........Is it worth it regardless of price being that one is a P and the other is a T?

 

The T9550 will have a larger cache that will yield better performance for games and such, but it will have a 35W TDP as opposed to the 25W TDP for the P8700. In other words, the T9550 will perform better but will also produce more heat and consume more power.

The performance difference it brings to the table will not be noticeable at all unless you run applications that make full use of the CPU's potential computing power. Which CPU to choose depends on your computing needs, so it's ultimately your choice; the extra $125 may be worth the performance premium if it matters that much to you. Personally I would stick with the P8700.

 

Bog said it very well.

I would also go for P8700. It has enough power, runs cooler and uses less power.

 

I dont think its worth the 125 either.

I got the P8700 and even with movie encoding and such... compared to my friend's T9550 its a matter of a few seconds here and there.

Add that up over a matter of a year and 8 hours of use per day... I guess you could save yourself 50 mins (I am kinda kidding with this statement)

 

The extra cache is worth maybe 5-10% performance wise, how much an advantage the clock speed is depends. Though its not like you hurting anything going faster. Does tend to be a case of diminishing returns though the higher up ya go.

 

Average Performance gain was 3.5% going from 2MB -> 4MB L2 Cache:
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2795&p=4

I expect an even smaller gain from going 3MB -> 6MB, since there aren't that many cache hits left in the 3MB configuration that 6MB will cure.

I'd go for the P8700 as well.

 

This shows the performance impact from 0.10 GHz + 3 MB cache extra.
http://www.anandtech.com/mac/showdoc.aspx?i=3246&p=12

 

Considering the fact that a jump from 2.4 GHz -> 2.5 GHz already corresponds to a relative clock gain of nearly 4.2% the average performance gain anand measured with 4.8% don't really sound impressive.

Since the TDP numbers - especially if you'r undervolting - are rather meaningless: Does somebody have some power consumption comparisons 6MB vs 3MB L2?

Especially under some load, since L2 caches in the higher sleep modes (C4, C6) get flushed and disabled anyway? At idle workload both L2 variants consume nearly identical power, but under load it's different. I only know of a comparison on a german site:
http://www.notebookcheck.com/Test-Intel-Core-2-Duo-Penryn-CPUs.7837.0.html

However the T8300 and T9500 used there have very different VID settings. The T8300 had the highest VID and therefore a rather high power consumption.

 

Personally I would not call 25 watt versus 35 watt meaningless. It will help battery life, temperatures and fan noise.

In my experience these differences will not disappear because of undervolting, as the lowest multiplier often does not allow much undervolting.

 

My experience is different.

Since you'r from netherland, you might understand / be able to read some german. Here are two independet references of why TDP bins are unrelated to power consumption:
http://thinkpad-wiki.nojoco.de/Vista_Stromverbrauch_senken#Der_Intel_Low_Voltage-Skandal
http://www.heise.de/ct/Wie-viel-Leistung-schluckt-meine-CPU--/hotline/136618

I agree that the 45nm parts for Santa Rosa platforms (e.g. T8300) may use a different stepping (namely M0 vs. R0) than the Centrino 2 platform types (e.g. P8600). And maybe some of the P type parts do allow 0.9250 V instead of 0.95 V for it's lowest possible VID.

But as a rule of thumb power consumption is a function of VID and frequency. Using undervolting I can reach almost any TDP bin with my T8300.

 

The P8400 I had did not allow any undervolting at it's lowest multiplier. Lower settings were not available with any of the programs I tried.

I have not tried undervolting any of the T9xxx CPUs. If they do allow undervolting at the lowest multiplier your point would be right.

 

Unless you play CPU/GPU hungry games or encode HD video, you don't need a T9550 CPU - P8700 is fast enough for most situations. I choosed a P9500 (25W TDP) for my new Latitude E6500, because I will work with AVCHD video - L2 cashe size is playing not a second role in Adobe Premiere - for now (with T9550) it is best price/performance CPU in the market. But for standard (general) use P8700 has a sweetest price without serios degrade in general performance.

 

No Core 2 Duo CPU at all allows undervolting at it's lowest multiplier. That's for sure almost by definition. It's mentioned in RMClock.htm FAQ section: It is also impossible to program a VID being lower than the Minimal VID reported by the CPU.

While you can unlock VIDs with RMClock UnlockVid registry key, it's useless since the CPU doesn't respect those and wont go lower than it's lowest possible VID.

Using low multipliers is useless anyway. Instead chose the highest possible FID that is stable with lowest possible VID. CPU will sleep longer and deeper this way (and thus consume less power and dissipate less heat). I just responded yesterday regarding this matter. If it's of interest for you, you might check:
http://forum.notebookreview.com/showthread.php?p=5054482#post5054482

 

Well when I have another Core 2 Duo laptop it sure becomes interesting.

I think you should make a separate post, because if this is all true it should become more known.

I expected lowest multiplier would be best for powersaving and long battery life, but you seem to know what you are talking about.

Edit: I see you already made a separate thread. Good work.

 

I'm kinda having regrets about purchasing the P8700 instead of the T9550. The reason for this is because when I was doing a Skype video chat yesterday my CPU was maxed out. By downgrading to the P8700 am I going to have issues?

 

If a 2.53GHz Core 2 Duo can't run Skype Video chat, it sounds like there's something wrong with either Skype or your software (os/drivers).

 

Skype can run on a 286, your processor isn't the issue. Actually, I'd be more concerned with why you would use skype, that technology is older than Windows ME.

 

LOL what program do you use to video chat? I use Skype and Google Talk but I like Skype better.

 

Right now I'm prototyping land-line video phone technologies with full real time video and sound. So when you start screaming and waving your hands in the air, the screen and sound quality don't get bogged down like they do with skype and google. We're currently migrating it to handheld devices, and when this thing deploys, it's gonna send skype out of business.

Right now skype and google are good for what they provide because there really is nothing else but for a lot of people the technology just sucks.

 

That's pretty cool! How will it integrate with IM clients on the PC side? I think what makes Skype, Google, iChat useful is that video chatting with your friends is so easy. You can see when they're online and just click on a button to video. Don't know if a land-line phone would be as successful (even if the video quality is better) unless it integrates with an IM client.

 

You're right! Landline video has existed for a few years now but it's not taking off because it can't communicate with pc's and mobile phones. Skype's problem is the technology itself is dated and you can't build upon it to expand to landlines and mobile phones. Although they have apps on phones now, the quality is so bad, that it's just not a viable option - as in, what's there is there but the quality won't be getting better than what it already is. For video calls to really be the future, the words need to match the lips in real time or the masses just won't care to use it.