Does the GT 445M in the new XPS use shared memory?

I ordered a 17" XPS with the GT 445M and 6GB of memory. But after doing some reading I am concerned that I may only have 3GB of memory useable by the system. That would also mean that the other 3GB that the graphics card is using would be very slow compared with dedicated graphics memory.

Does anyone know how the memory is setup in these laptops?

 

I think the graphics Cards in those XPS have dedicated RAM and do not share it with the memory. I only have 4gb of memory in my XPS 15 and a 2gb NVIDIA 435 gt that would mean I'd only have 2 gbs of Memory Left and that'd Be really really Slow...

 

I hope your right, but several places I have read reference the graphics card using DDR3 memory (not GDDR3/5). Maybe those were incorrect...

 

They're incorrect. It is GDDR3, for the XPS 15 at least.

 

All GPUs on a performance laptop have at least some dedicated memory.

I'd assume that it is actually 3GB dedicated memory, but remember having a 3GB GPU doesn't mean it's a "good" card.

 

From Dell's spec page for the 17":

Memory
4GB Shared Dual Channel DDR3 Memory
6GB Shared Dual Channel DDR3 Memory
8GB Shared Dual Channel DDR3 Memory
12GB Shared Dual Channel DDR3 Memory
16GB Shared Dual Channel DDR3 Memory

But then from http://content.dell.com/us/en/home/d/help-me-choose/hmc-nvdia-graphics.aspx?ref=CFG

Why dedicated graphics memory?
Dedicated graphics memory is designed to free up system memory, which helps improve the overall system and graphics performance of a laptop. The NVIDIA performance-level graphics processor fitted on XPS laptops offers supercharged performance in high-definition (HD) video playback and photo browsing, and high-resolution graphics for next-generation gaming.

 

How do you know the XPS 15 is using GDDR3 for its GPU?

Can somebody please explain the difference between DDR3 and GDDR3.

Thanks.

 

The 435/445 specs from Nvidia call for regular DDR3 memory. However, that doesn't mean that it's shared with the DDR3 main system memory. It has it's own dedicated memory, it just uses cheaper regular DDR3 than slightly faster/more expensive GDDR3. GDDR3 and DDR3 are not the same thing, and Nvidia would not label their specs as regular DDR3 if it did actually have GDDR3.

 

Graphics Double Data Rate 3 is a graphics card-specific memory technology, designed by ATI Technologies[1] with the collaboration of JEDEC.

It has much the same technological base as DDR2, but the power and heat dispersal requirements have been reduced somewhat, allowing for higher performance memory modules, and simplified cooling systems. GDDR3 is not related to the JEDEC DDR3 specification. This memory uses internal terminators, enabling it to better handle certain graphics demands. To improve bandwidth, GDDR3 memory transfers 4 bits of data per pin in 2 clock cycles.

GDDR3 - Wikipedia, the free encyclopedia

 

They're completely different. I could get technical, but what it boils down to is that GDDR3 can send more data per clock cycle. It's faster, and GPUs need to be fed quite a bit otherwise they run into a bottleneck.

DDR3 is just the normal crap CPUs use, even a low end GPU would run into a bottleneck with it.

 

I don't know why they are calling it DDR3, but it cannot be DDR3 800MHz, because that only has 12GB/s bandwidth, whereas GDDR3 800MHz has 25.6 GB/s. This is what the 5730 has, and that's the memory bandwidth listed for the 420M, 425M, and 435M.

 

GeForce GT 435M
GeForce GT 445M

 

The 435M would need DDR3-1600MHz to have 25.6 GB/s bandwidth. What are the chances Nvidia marked THAT down wrong compared to the chances they forgot a G?

 

Another interesting thing is that dell shows the memory interface for the GT 445M in the 17" to be 192 bit, and the NVIDIA site seems to show that a 192 bit interface goes with GDDR5 memory.

 

Then it probably uses GDDR5. It would make sense if Dell positioned it against the ENVY 17, which comes with a 5850 that uses GDDR5.

Well well well... these laptops are turning out to be quite the screamers eh? 445M GDDR5 can pick up and roof a 5850 lol.

 

Ooh, GDDR5 in a Dell laptop that isn't alienware!

Darn Dell sell XPS 17 here

 

I just chatted with a Dell tech (not sure how reliable their info is). Here is the info I got...



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2:47:58 PM EDT Joanna B
Welcome to Dell US Chat! My name is Joanna B and I will be your Dell.com Chat Expert. I can be reached at [email protected] or via voicemail at 1-800-379-3355 Ext-2160085. How can I help you today?
2:47:58 PM EDT Joanna B
hi Barnett25
2:48:32 PM EDT Barnett25
Hi, I have a rather technical question about the new XPS 17" laptop specs
2:48:57 PM EDT Joanna B
Thanks for chatting in! I'll be happy to assist you today Barnett25
2:49:01 PM EDT Joanna B
ask away!
2:50:04 PM EDT Barnett25
I cant tell from the website, is the graphics memory for the NVIDIA GT 445M DDR3, GDDR3, or GDDR5? I seem to find conflicting info
2:51:39 PM EDT Joanna B
I'll be glad to check it for you Barnett25, are you looking at a specific deal right now?
2:52:41 PM EDT Barnett25
I am just looking at the 17" XPS with the i7 processor, and GT 445M graphics, but there is a big performance difference with that chip depending on which memory it has, and I want to be sure of what I am getting
2:53:44 PM EDT Joanna B
I understand, checking on the system now.
2:53:49 PM EDT Barnett25
thanks!
2:56:05 PM EDT Joanna B
still checking..
2:56:20 PM EDT Barnett25
no problem, i figured this would not be an easy thing to find
2:58:32 PM EDT Joanna B
Thanks for waiting Barnett25!
2:58:36 PM EDT Barnett25
no problem
2:59:08 PM EDT Joanna B
I checked on the XPS 17 and its video card has DDR3 memory
2:59:55 PM EDT Barnett25
i see, can you tell if it is using part of the system memory? In other words, if I get a laptop with 6GB of memory, are 3 of those going to be used up by the graphics card?
3:01:14 PM EDT Joanna B
No,since these cards are dedicated so they have their own memory to use
3:01:28 PM EDT Barnett25
ok, thanks! Thats all I needed to know!

 

Well, I could be wrong-- I'm not an expert by any means. And if I am, well, I'll get a refund. There's no way my 5730 is getting replaced by that.

 

Yeah, it's looking more and more like I'm wrong. OTOH, this explains why/how Dell is putting so much memory on these. DDR3 is cheaper than GDDR3, and denser too.

Dell just struck out in my book. My SXPS is looking a lot more attractive now. When my XPS 15 gets here, I'll benchmark it I guess. But I'm not keeping it.

 

Based on its source (Dell support) its very, very unreliable! We should get some real reviews on these systems soon and then we will know for sure what memory is being used.

 

The answer to the question is that it probably does use shared memory, but it also will have a fair amount of its own to chew through first. Shared memory is only really there as a buffer so games don't crash if they call for too much momery, that's not to say that things will run well with shared memory though.

 

Not necessary. I believe Dell. After looking into it, I found out Nvidia lists the actual clock and not the effective clock. The effective clock for the memory, then, is 1600MHz, and it DOES have 25.6GB/s of bandwidth like it says in the spec sheet.

As for the 445M, I spoke to Dell and they had trouble looking up the specifications for it. I was assured that they would send me an E-Mail as soon as they do. That was weird.

Looking at the amount that it has though, there's no reason to assume that that isn't DDR3 as well. GDDR5 is expensive, and even more expensive the denser you need it.

 

I'd really like to see the results of that. It'd be great to have some real, reliable numbers to look at than all the speculation that is the rule for now. I assume you got the one with the 435m?

 

I agree it does look like it may be using DDS3 memory. Im not saying they are right or wrong, simply stating that the source (Dell technical) has been proven to be very unreliable many times here on the forums.

 

any new informations? Thats very poor from Dell, I´ve also chatted with support in Germany and US, noone there knows which kind of memory their own (!!) producs are using! Thats like you go to a car dealer which want to sell you his newest car, but don´t know how many horsepower this car uses. Unbelievable.

 

In all actuality, the 445m is a pretty powerful video card.

Don't be too disappointed. Look at some real world benchmarks.

 

Mobile Graphics Cards - Benchmark List - Notebookcheck.net Tech

Computer Games on Laptop Graphic Cards - Notebookcheck.net Tech

I did a four way comparison 4670 vs 5730 vs 435m vs 445m

not a ton of comparison stats out for the newer nvidia's, however from what is out, it is as expected 445m>5730>435m>4670 ...

 

That sounds about right. The 445 with DDR3 should be a little faster than the 5730, and the 445 with GDDR5 should be significantly faster. I just wish they'd offer the 445 with the XPS 15, that would be worth getting.

 

This screenshot from the XPS 17 thread is also what I show with GPU-Z:

 

sorry im not trying to trash this topic but does the nvidia GT 445M graphic card still overheats and burns like the 7000s and 8000s series? ....just curious

 

I can't say for certain on the 445m but my 425m in my 14" maxxed out at 78 degrees even in furmark which is known to torch cards. I would say the 4XXm series is a cool running card if nothing else

 

This is what CPUID Hardware Monitor on my L701x showed

max temp 46 C (114 Farenheit)
so no, doesn't run hot.
Rooster

 

All this talk about overheating and I can only remember 1 person who actually provided figures that were a little worrying and that's because they had OC'd. I think the pasting on some machines have been pretty poor and therefore are showing temps roughly 5 degrees more than they could be but when I hear stuff coming from people about frying eggs blah blah It just makes me laugh.

 

For those who are still interested in the performance of the 445M
please visit this thread and post your results...
http://forum.notebookreview.com/del...ic-driver-vs-modified-nvidia-driver-445m.html
Thanks,
Rooster