Upgrading M6400 GPU

I've been pleased with my M6300, so I decided to buy a used M6400. Once I confirm that everything is working, I intend to upgrade the video, and possibly the CPU. The model I purchased has the base video chip, a 2700M. Is there any particular reason to prefer the 3700M over the ATI M7740? Both seem to be about the same price and have similar performance, at least according to gaming benchmarks.

One final question that the Dell manual doesn't seem to address: Is it necessary to apply thermal paste when replacing the CPU/GPU heatsink assembly?

 

the driver of 3700M support better professional software than the driver of ATI M7740

yes, you need apply thermal paste when replacing the CPU/GPU heatsink assembly

 

Is it ok to reuse the thermal pads?

 

and, m7740 is much cooler than fx3700m, even fx2700m's single pipe heatsink can handle it well
what about fx2800m, same performance as fx3700m and much cooler
btw fx3800m/m7820 work on m6400 too, but the most powerful quadro 5000m remains unknown......

not recommend

 

In that case, what thickness pads should we use? I have some .5mm at home but I wonder if that's too thin for most cases

 

m7820's perfonmance looks like not far from 5000m.
the m7820 is stable in m6400? it's cooler than Fx3800m? do we need some modification of the card or the bois to install it?

 

so u can stack 0.5mm to 1.0/1.5/2.0
but if the old pads not out of shape nor spill oil, its ok to reuse

furmark load, m7820=65+c fx3800m=85+c
no need modding anything, but better update to latest bios
my case is the screen will show nothing during bootup(black), till windows loading animation appear
and when i output to a external monitor, i get freeze&lockup when disabling laptop monitor, need hard reboot
(dont know if above just my case or incompatibility)

 

Thanks for your answer, quite helpful

 

Just to post an update - I went ahead and ordered a M7740. I kept an eye out for a M7820, but nothing came up on eBay over the course of a couple of months. Since my interest is gaming rather than CAD, I didn't care about certifications.

I also got a Q9100 to replace the stock T9550, but I wasn't paying attention and ended up with an engineering sample. Apparently it has an unlocked multiplier, but NO temperature sensors. Should I be concerned?

 

m7820.....many list it as hd5870, since its core is as same as hd5870m
DELL PRECISION M6400 1GB ATI HD5870 MOBILITY V.CARD | eBay

es q9100......see what spec you got
http://forum.notebookreview.com/har...ades/396594-qajf-vs-qavr-vs-qavk-vs-qdrs.html