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The 4800 series Driver, OCing, Cooling and Tweaking Thread

Megasty said:
Yeah, which means if the 4870's mem is at 900MHz its effectively running at 3.6GHz :wtf:
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Which would be bomb...And overclocking would get some super yields.
 
Ok, Here is the PDF for GDDR5, reading now...

-Ok they call it GGDR5?? I think that's a typographical error...

Ok I am not reading anything that suggest QDR but GDDR.


Megasty said:
Yeah, which means if the 4870's mem is at 900MHz its effectively running at 3.6GHz :wtf:
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Yeah no kidding, that's why I found the PDF (above) nothing in it suggest QDR.
 
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Looks like just double to meh....:(
 
EastCoasthandle said:
Ok, Here is the PDF for GDDR5, reading now...

-Ok they call it GGDR5?? I think that's a typographical error...

Ok I am not reading anything that suggest QDR but GDDR.
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The clocking section gives the answer. Its just GDDR with a super high single clock, like the speed difference between GDDR3 & GDDR4. But this junk seems to blow all of that to new heights.

I can see how people think its QDR, it should be fake-QDR. It has 2 write clocks but they are both running at the same speed. So if the CK was 900mhz then the WCK would be 1800mhz, but since there's 2 of them processing separate data then it would work 'twice' as fast as a single WCK. In essence the effective speed would be 3600mhz...
 
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No. GPU-Z reports real clock, not effective.

I don't think it's QDR. If it was, it would be called GQDR5, not GDDR5. So if stock is 900, it should be 1800MHz effective.

But keep in mind, some 4870s come with GDDR3. Was the GPU-Z report of 900MHz with GDDR3 or 5? I'm guessing 3.

Edit: Yeah I had a feeling we were still a little ways away from anything QDR.
 
It says GDDR5 on the GPU-Z

On memory, saw this posted at B3D:

From the extremetech preview of GDDR5: link

Bandwidth first: A system using GDDR3 memory on a 256-bit memory bus running at 1800MHz (effective DDR speed) would deliver 57.6 GB per second. Think of a GeForce 9600GT, for example. The same speed GDDR5 on the same bus would deliver 115.2 GB per second, or twice that amount. Take any GDDR3 bandwidth on a given clock rate and bus width and double it, and you get GDDR5's bandwidth. Of course, the marketing guys love big numbers and would undoubtedly not call it 1800MHz, just as 1800MHz GDDR3 is really running at 900MHz. Expect the marketing guys to call memory at that speed 3200MHz.
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Obviously an error in GDDR5 effective speed (should be 3.6GHz for 4 x 900) but it seems to suggest that GDDR5 takes the effective memory of GDDR3 and doubles it again. Interesting.


BTW for anyone interested, the 4850 CF results were compiled here by someone:

http://www.hardforum.com/showpost.php?p=1032627938&postcount=20
 
DanishDevil said:
No. GPU-Z reports real clock, not effective.

I don't think it's QDR. If it was, it would be called GQDR5, not GDDR5. So if stock is 900, it should be 1800MHz effective.

But keep in mind, some 4870s come with GDDR3. Was the GPU-Z report of 900MHz with GDDR3 or 5? I'm guessing 3.

Edit: Yeah I had a feeling we were still a little ways away from anything QDR.
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Yeah, like those 4870's Tom's got....they had GDDR3, as they were engineering samples.

Edit: Wow:eek:....those CF scores are pretty bomb. And, even the single scores there are super....Like this:

Gigabyte X38-DQ6 + Q6700 @3GHZ
Assassin's Creed, 1920x1200, Max Setting:
HD 3870 -> 35 FPS
HD 4850 -> 60 FPS

Wow...
 
Interesting...why don't they call it GQDR5 then :confused:
 
DanishDevil said:
Interesting...why don't they call it GQDR5 then :confused:
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I think they're just spliting hairs. Regular GDDR just has a clock & one work clock while GDDR5 has a clock & 2 work clocks. It would technically be QDR if it had one clock for each work clock but if the bandwidth is high enough, & it certainly is, then it wouldn't matter anyway. Damn this mess is gonna be fast.
 
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Well we all expect you to post the first results maybe?
 
I hope so. Gonna be about 2 weeks now :(
 
Prolly gonna be about that long till I can actually use any of my DDR3 boards. :(
 
Crysis @ 1920x1080 @ High Setings @ DX10 Using x-fired hd4850's
cfdx101080iu4.jpg


Credit to mascaras-http://www.xtremesystems.org/forums/showpost.php?p=3071110&postcount=1

Looking good.4870 x-fire will :rockout:
 
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Was that on your 256MB 3850?
 
tigger69 said:
No,its crossfired 4850's.Check the link.
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D'OH!

Yeah I see, didn't notice the Crossfire 4850 a the top of the picture. I was going to say that's complete BS on a 256MB 3850. :roll:
 
InnocentCriminal said:
D'OH!

Yeah I see, didn't notice the Crossfire 4850 a the top of the picture. I was going to say that's complete BS on a 256MB 3850. :roll:
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It's bloody impressive now you know it's a 4850 CF eh? :P
 
Darknova said:
It's bloody impressive now you know it's a 4850 CF eh? :P
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Damn right, especially at that resolution. However, I really hate Jaggies. I mean really freaking hate them so I'd be interested to see how well they work with AA enabled.
 
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