Overclocking Extravaganza: GTX 275's Complex Characteristics
by Derek Wilson on June 4, 2009 5:35 AM EST- Posted in
- GPUs
Memory Overclocking
Data availability is important in the performance of GPUs, and AMD and NVIDIA pack huge amounts of bandwidth into their designs in order to accommodate this need. While AMD's high end parts have moved over to the newer, less tested, GDDR5, NVIDIA will stick with GDDR3 until at least their next architecture revision (though it is still unclear exactly what memory technologies NVIDIA will support beyond the current generation). This does mean that NVIDIA needs twice the number of pins to achieve the same bandwidth (at the same clock speed), but this isn't a huge problem for the already monolithic G80 and GT100 based GPUs.
With the 448-bit wide connection to GDDR3 memory, NVIDIA's GTX 275 needs to run it's RAM at a higher clock speed in order to achieve the same data rate the Radeon 4890 can hit with it's 256-bit GDDR5 bus. Certainly fast GDDR3 has had time to mature and is highly available. This and the fact that demand is still much higher for GDDR3 mean that NVIDIA is saving some money on competitive memory subsystems. But needing a higher baseline clock speed to compete with AMD's solution could mean less overclockability overall.
We were able to get a greater than 23% clock speed increase out of our 4890, but the best we could manage between a couple of GTX 275 samples was a little more than 14%. Starting out with very nearly the same memory bandwidth, our overclocked AMD part comes out ahead in absolute terms.
It is important to remember, however, that absolute bandwidth doesn't matter as much as how well the bandwidth matches the demand of the GPU. This isn't something we can easily ascertain, but our look at the impact of only overclocking memory certainly shows that the bandwidth NVIDIA chose for the GTX 275 is a good match for the core and shader clock speeds with which it is paired.
1680x1050 1920x1200 2560x1600
We will be digging deeper into how memory speed impacts performance after we look at the rest of our scaling tests, but without any other assistance, just overclocking memory is not going to gain a lot for the GTX 275.
Facebook
Twitter
RSS
43 Comments
View All Comments
SiliconDoc - Monday, June 22, 2009 - link
Not only does the gtx275 beat the 4890, but the gtx260 beats the 4870 !http://www.techspot.com/review/164-radeon-4890-vs-...">http://www.techspot.com/review/164-radeon-4890-vs-...
..
Oh gee, I guess I should follow dereks chart instead... ( GAG ! )
SiliconDoc - Monday, June 8, 2009 - link
" Given the performance and pricing of Phenom II and the upcoming Radeon 5000 series, if AMD does not pull into black [records a profit] and achieves great sales success, we don't know what needs to happen in order for AMD to actually earn some serious money. "LOL
Will ATI ever make a profit ? We keep hearing how smart they are and how they can really make money while NVidia's monster vore costs nvidia so much ! LOL
Awwww- poor ati can't make dime one while nvidia keeps posting profits...
http://www.brightsideofnews.com/news/2009/6/3/ati-...">http://www.brightsideofnews.com/news/20...-has-the...
----
Any red roosters gonna stop crowing about smaller gpu cores and their savings for ATI who loses money every single quarter, anytime soon ?
Probably NOT - they're so smart, so wise about making gpu's.
SiliconDoc - Saturday, June 6, 2009 - link
Better be careful - from their 4890 extravaganza overclock article they did first and used the results in this comparison against nvidia:-
" We absolutely must caution our readers once again that these are not off-the-shelf retail parts. These are parts sent directly to us from manufacturers and could very likely have a higher overclocking potential than retail parts. "
YES WE KNOW - NOW YOU'VE TRANSFERRED YOUR RESULTS HERE AGAINST A 703 CORE THAT IS LOWER THAN THE FTW EVGA GTX275 you can but stock faster!
---
You had BETTER look at a few other places that aren't so GD biased it's built in - and Derek is insanely red rooster fan boyed, and hates Nvidia, obviously, like so many little cluckers here for over a year now.-
---
Jeepers- a special 4890 up against non overclocked gtx275 in the 4890 article, then transfer the special results here, and put NOT a regular clocked 4890 as in the other article to be half fair - but jam the massive results in from the special cards they got...
---
I'm mean you really can't screw it up much worse than that.
They did their best red rooster bias blab possible, I'll say that much for em, and covered it up as best they could.