I wonder if the refresh will 'fix' the relatively high idle power consumption of the 48-series in comparison to nVidia's equivalent.
I wonder if the refresh will 'fix' the relatively high idle power consumption of the 48-series in comparison to nVidia's equivalent.
Looks like the number of transistors will decrease to 828 million in the RV740 from the 956 million in the RV770:
http://www.theinquirer.net/inquirer/...nm-gpus-arrive
I think you're reading too much into the situation CAT, it'll be the same as any other mid-range card launch:
- The lower model will perform at a level that will justify it's lower price tag, and will also be sold in a version that has more memory (so OEMs will like that as it raises spec's) but that won't buy it any real extra performance due to inherent design limitations (the 128bit memory controller).
- The higher model will have enough performance to give the next model up a run for its money, but will never be sold in a configuration that will actually let it completely surpass it (don't expect to see a 1Gb GDDR5 card...).
- The crippled high end cards (in this case 4830s) will coexist with the new midrange if just as a means of shifting the stock and will probably sell because the number is higher (there might also be a performance benefit somewhere due to the high end origins as has happened in the past).
Personally I'm more interested in seeing what the 4890 will do to the 4870 prices, or whether batches of 4830's are going to start showing up as being a bios flash away from a 4850
Seems that that a HD4850 GDDR5 is in the works from Gainward:
http://www.fudzilla.com/index.php?op...2619&Itemid=34
Considering that an HD4870 can be had for £140 to £150 it will be interesting to see how much this costs!!
The TDP is reasonably low:
http://www.fudzilla.com/index.php?op...2866&Itemid=34
The GDDR5 cards use 80 watts so it seems to need additional power from a connector but not much more.
Considering the initial performance figures this great good still!!
Seems the GDDR3 version will probably be bus powered!!
Based on Gainward's usual pricing, I suspect that it will be more expensive than some 4870s (but presumably cheaper than Gainward's): to wit: Gainward's 4850 Golden Sample 512MB is currently £160 on ebuyer; their stock 4870 is £175, so I'd guess at about £170 (they do a 1GB 4850 which currently costs £173 on ebuyer).
As to the 4770 / 4750 - they are definitely looking like good cards if they can come in sub £100. More tricky decisions and moaning about lack of finance ahead, then
Here are the full specs of the HD4770:
http://en.expreview.com/2009/03/31/a...-unveiled.html
It seems to have slightly less memory bandwidth than an HD4830 but almost the same processing performance as an HD4850.
Thanks for the link CAT - only one problem: Opera says it has been trying to open that page for 45 minutes so far, without success!
OK, finally got the specs from the expreview homepage. Given they're almost identical to the 4830 but with a 30% clock boost (countered by a 10% loss in memory bandwidth), it really should perform very close to the 4850. It's going to be an interesting couple of month's, graphics-wise...
Last edited by scaryjim; 31-03-2009 at 12:32 PM.
TBH I think that if the specs are accurate then OC versions of the HD4770 will be around the same speed as the HD4850. If they clock the GPU to 800mhz and the RAM to around 900mhz to 1000mhz it should be achievable too. It would make more sense then to use the RV770 cores for the HD4870 instead. I would imagine that the cost of GDDR5 is now dropping too especially if the HD4830 replacement is using it! The drop in power consumption looks good too!!
There are some more details here:
http://www.techpowerup.com/89713/Rad...d_for_May.html
It seems to have a dual slot cooler which looks like a shorter version of the one in the HD3870. Seems to have heatpipes too!
The cooler seems to fit the white outline seen on the engineering card. Also additional capacitors are present too in the locations indicated by white circles on the engineering card. Hence it looks like this probably is the first official picture of the card with its reference cooler.
The card will be released on May 4th it seems.
Last edited by CAT-THE-FIFTH; 31-03-2009 at 03:49 PM.
And the 4890 of course
Certainly the roadmap slide shows it basically sitting between the 4830 and 4850 but at the same price as the 4830, which I guess means that the 4830 will be completely replaced. I suspect we'll still get a few 4850s from speed-binned RV770 cores, and the rest will go into the 4870 and 4890.
I assume they won't bother with a cheaper version of the RV740, and will just price-chop the existing 4670s down to near £50 again (where they entered the market 6 months ago, ironically...)
The RV790 core in the HD4890 is meant to have a slightly different pin arrangement to the RV770 found in the HD4870. Supposedly there is a change in transistor count too with the RV790 having a few more.
Ok by the specs you've got a really odd card there.
vs 4850
higher gpu clock
fewer streams
slower memory
lower bit rate
higher data rate (gddr5)
Now I remember how to calculate gddr3 bandwidth, but I cannot remember where some of the numbers come from so how it directly effects them.
if thoes numbers for gddr5 are correct, then over clock the memory and you should get the same bandwidth as the gddr3.
the higher data rate seems to make up for the halving in bit rate
So the 4890 is a different core? Because on the specs it *looks* exactly the same! I'd assumed they'd just managed to yield sufficiently good RV770s to bump up the stock clocks...
As I understand it GDDR5 is a bit of a misnomer, because the RAM is actually Quad Data Rate. But basically yes, you get double the transfer rate compared to GDDR3 at the same clock, so you can half the bit-width and get the same transfer rate. I assume that makes it cheaper to manufacture the board, as you can have less memory chips at a higher density?! *shrug* (why doesn't hexus have a shrugging smiley, I ask you!)
It seems that the HD4750 may have a power connector:
http://www.fudzilla.com/index.php?op...3162&Itemid=34
Some more HD4770 details from AMD:
http://vr-zone.com/forums/418725/hd-...and-price.html
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