4850@750Mhz vs 4870

[Truckchase!]

You shouldn't have to do that. It's a shame that the dozens of hardware sites, that had both cards in their possession, didn't run this kind of test so you wouldn't be put in that position. It's like they took for granted that the 4850 would never hit the core speed of the 4870 and just ignored the possibility the GDDR5 is all fluff.

I enjoy doing this stuff. Most reviews aren't very good. Quantity does not necessarily equal quality. I appreciate the concern tho....

[adpr_02]

Here is my 2C. I'm sure it's not much, but just shows that memory does help - at least in synthetics.

According to Legit Reviews, the HD4870 gets P8769 3dmarks.
Their processor is the newer Q9770.

My system, with the card clocked at 720/1050 and my q6600 at 3.6ghz I get P7850 marks.

The net processor performance, I am guessing is the same since, although theirs is 3.2ghz only, it's the newer version with higher performance/clock. Also, I do not think the CPU score has a very large impact on the overall score.

Seeing as how my clocks are so close to the 4870 (with the memory overclocked, even) and my score is so far away, I am guessing that the GDDR5 does have an impact, but it is not that large. I am sure that if I pushed my core to 750 I would jump my score to P8100.


Just my 2C

[aldamon]

Here is my 2C. I'm sure it's not much, but just shows that memory does help - at least in synthetics.

According to Legit Reviews, the HD4870 gets P8769 3dmarks.
Their processor is the newer Q9770.

My system, with the card clocked at 720/1050 and my q6600 at 3.6ghz I get P7850 marks.

The net processor performance, I am guessing is the same since, although theirs is 3.2ghz only, it's the newer version with higher performance/clock. Also, I do not think the CPU score has a very large impact on the overall score.

Seeing as how my clocks are so close to the 4870 (with the memory overclocked, even) and my score is so far away, I am guessing that the GDDR5 does have an impact, but it is not that large. I am sure that if I pushed my core to 750 I would jump my score to P8100.


Just my 2C

If you did overclock to 750 and hit P8100, you'd only be 8.25% off of the 4870's pace. Games are showing an even smaller difference.

[adpr_02]

I've got close to that. I looked at their score, and didn't realize they shwed the gpu and cpu score. So I get my cpu score close to theirs, and bench again, this time with my card at 735/1060.

I got 7121 marks on my gpu score
They got 7890 marks on their 4870 gpu score

My cpu score was 13295
Their cpu score was 13132

I noticed that cpu speed does not affect the gpu score at all (My gpu score was exactly identical at 3.6ghz and 3.8ghz.)....

Overall, I got 8050 marks
They got 8769

My gpu score jumped more than 100 marks by increasing the gpu frequency 15mhz (and memory 10mhz). At 750/1050 this card should score around 7250 gpu marks which would bring it close to the 4870.

I am guessing that this card clocked at 800/1200 should EASILY overtake the 4870. I'll try that when I get the right size variable resistors.

[keiths]

1. What performance drop off? GPU, memory, both? Be specific.

2. You can't compare to a review. They have different base hardware, different OS, different benching techniques, etc. On top of that I can't guarantee the skill of the tester. (nor should you)
3. Max overclock will vary on a card by card basis, but obviously will reach an average. (as I believe you're getting at) However, the point of this thread is not to compare to Nvidia products, but to compare a 4850 vs. A 4870.

My point is that the main difference between a 4850 and 70 is the memory bandwidth. (yes I realize the voltage circuity is better on a 70) Given this information, one can conduct tests to see if the 4850 is memory bandwidth limited and answer the majority 4850 vs. 4870 question, which is the premise of this thread. That being said, I think I'm going to unwrap my 4850 tomorrow and do some tests since I have the automated scripts to do so. The offer still stands if anyone wants to buy this card since I'm getting 70 from FXVideoCards on Wednesday.

Edit: Oh snap, I didn't see that it was you that opened the thread until now KeithS.... do you want to change the context? I can't provide Nvidia data.... I'll just say they're "for the most part, faster and more expensive"

1. Memory. I'm interested in seeing how big a benefit the 4870's memory gives.

2. You can, and we already have, roughly. In spite of different platforms, there are trends in the results.

3. Of course, and yes, average.

I had added it since gurusan provided an oc result. That a 4850 can reach 260 and 280 performance makes me interested in seeing those results as well.

[gurusan]

The 4850 can surpass the GTX 280 The guy with .2 fps more than me has a highly clocked 45nm quad @ 3.7ghz while I only have a 65nm dual core at 3.6ghz. Also you should notice his GTX 280 is overclocked quite a bit :p

[Lightman]

The 4850 can surpass the GTX 280 The guy with .2 fps more than me has a highly clocked 45nm quad @ 3.7ghz while I only have a 65nm dual core at 3.6ghz. Also you should notice his GTX 280 is overclocked quite a bit :p

That is very impressive!!

Congratz!!

[keiths]

Yep, what I expected from linear extrapolation of your 810 result. What's your cooling now gurusan? Is 1680x1050 your max/monitor resolution? I'd like to see where the 4850's memory peaters out. And where is that chart from?

[gurusan]

on watercooling. 27-28c idle 36-38c load.

And yeah 1680x1050 is my max resolution. The chart is from a private forum so I can't really share it here :p

[aldamon]

I'm ordering one of these bad boys when I get back from the beach.

[keiths]

What's your water cooling setup?

[gurusan]

Laing D4 --->XSPC Edge--->Maze4--->Alphacool 120.3

[zaraza]

in order to reach those speeds could i do it on AIR with a accellero s1 v2 with 2 120mm fans? Also the pencil volt mod, is it safe to do with an S1 on it. How high will i be able to clock with the pencil mod? I want to try it when i get my 4850 next week. Also what kind of pencil did you use for the mod?

[gurusan]

you should be able to do high 850-900mhz on air i would think. And I just used a #2 pencil

[zaraza]

Dang gurusan thats awsome! i really want to buy the 4850 now and try the mod, i was thinking about buying it from besbuy inorder to have the option to return it if it goes wrong. lol. but newegg gives 2gb of ddr2 for free with a visiontek. In the techpower article it said i wont get more than 1.4 on the vddc, is that true? Please stick with me and help me understand this. This is my first time considering to volt mod.

[zaraza]

the only problem i would have from overclocking, is that i have to flash the bios to get the speeds right?

[keiths]

Long ago I did a homemade water setup for my k6; square PCV block caulked right onto the CPU Still have the bilge pump I used(attwood v450, 450GPH@13.6v so ~= 397GPH/1503LPH@12v vs 1400LPH for the Liang D4,) and tubing. Also have an AC condenser/evaporator from a 90s Civic that I can use as a radiator, which is as tall as my tower case, slightly narrower, ie big for this use, which has a half and quarter inch inlet/outlets. Leaves coming up with a container to hold the pump, scrounge something up, and the water blocks.

[aldamon]

Can we get a list of expected overclock and maximum voltage per cooling option?

Is this about right?

Stock cooler with higher fan speed
1.3V? 800MHz?

Upgraded air
1.4V? 850MHz?

Water
1.5V+? 900MHz+?

[gurusan]

910mhz on 1.45v for me under water

[zaraza]

someone with a 4870 really needs to step it up and post comparisons to 4850 oc's

[dnottis]

910mhz on 1.45v for me under water

What block?

[gurusan]

What block?

maze4. 27c idle 36-38 load

[dnottis]

maze4. 27c idle 36-38 load

any problems with it fitting? no mods or anything right?

[dnottis]

Ive got a Q6600 65nm @ 3.6Ghz, 4870 @ stock I scored P89xx. Dont remember the exact number but was just under 9000.

I will run Crysis 1680 later, what settings are all the ones in the spreadsheet run at? 1680x1050, very high, no AA?

[jaredpace]

dudes, hunch: r700 will be slightly faster than two 4850's in crossfire.
i checked some benchies, 4850 averages around 79-80% the performance of a 4870, i think the extra 125mhz adds about 17% while have gddr5 adds the next 3-4%.

if the plx bridge doesn't do anything super for increasing r700's performance over 2x hd4870 in old-fashioned traditional [two-pcb/two-pcie] x-fire, then we should expect R700 to be 4% faster than 4850 x-fire (which still eats up a GTX 280 for the performance crown). Nvidia loses come August! Wonder if they take the lead again with 55nm gt200?

edit: just realized i posted this in the 4850 vs. 4870 core speed comparison thread, but it still has relevant information. I agree with this guy 100%:

Yeah, but that 25% difference was at stock speeds. 750 is 20% higher than 625, so are we to assume that at stock speeds, the GDDR5 only gives the 4870 a 5% advantage, clock per clock? That's a pretty crappy value if so and would explain the BIOS lock. I'm curious to see if that gap widens with higher core speeds.