Sign in with
Sign up | Sign in
Your question

Replacing My 3870x2

Last response: in Graphics & Displays
January 3, 2010 11:46:04 AM

I was wondering if anyone here could help me with upgrading my graphics card. A few years ago I purchased a Dell PC (in hindsight, not such a great idea) that had an array of relatively high-end components, including a 3870x2. It has recently started behaving erratically and is no longer state of the art, so I cast me eyes towards the 5800 series for an upgrade. However, several issues have become apparent:

1. Many people on forums like this talk about 'bottlenecking': how one CPU will bottleneck that card and stuff like that. I have a quad-core Intel Q9400 (default clocks @2.66ghz). Will putting a decent GPU alongside it be a waste of time?

*Please bear in mind I am unable to overclock any components in the system due to power limitations and Dell's locked-down BIOS.*

2. Power Consumption. I thought the 3870x2 was a horrendously power-hungry card, so was relatively confident that I could support any single GPU card quite happily. However, I am completely unable to work out what other cards I am able to support. Thanks again to Dell PSU upgrades are not possible.

However, as my card is at default clocks for a standard 3870x2, I though it would be relatively easy to find in reviews the 3870x2 power consumption. Unfortunately, all the reviews appear to disagree, with 100W differences in power usage with the ones I looked at.

According to Dell's specs I have a 425W PSU, but, in another brilliant move, I have discovered they rate their PSUs totally differently to normal sellers.

So, the question boils down to:

a) Does a 5870 use more power than a 3870x2 at peak power usage? (default clocks all round)
b) If it does, could I use a 5850 instead?

Thanks in advance for any advice.

EDIT: I run at a relatively low 1440*900 resolution.

More about : replacing 3870x2

January 3, 2010 1:10:33 PM

1. about bottlenecking, here's a nice article about matching a cpu for 5870
Your Q9400 should be pretty close to PhenomII at 2.7GHz, so in the end you might end up with 100fps instead of 175fps with i7@4GHz with the low resolution you are using. It might be wiser to buy the 5850 instead. (but on the bright side, you can bumb up the details and aa/af without performance penalty :)  )

2. power
3870X2 uses around 170-180W (looks like they didn't actually measure it, but more like calculated and made an educated estimate...)

5870 max around 144W under games (stress testing pushes it little over 200W)
5850 108W and 150W

To sum it up, I'd rather go with the 5850. You won't gain much extra performance with 5870, and 5850 is cheaper and less power hungry.
January 6, 2010 6:38:45 AM

Thanks for the help, 5850 it is.
Related resources
January 6, 2010 7:04:38 AM

The HD5850 is a good choice. You must have payed an insane amount of money for that Dell.
January 6, 2010 7:17:36 AM

It was on sale, but still cost £1.3k. Admittedly I ordered the premium 3year support, which was a total waste of money as I've never used it.
January 6, 2010 7:51:22 AM

Suggest you also change your PSU along with the GPU. Depends on what your monitor is also. What's your monitor? What resolution do you game at?

Seriously the support that they give for PC's is useless, whatever the problem is we can 99% of the time solve it ourselves. And 1.3k pounds is a lot of money!
January 6, 2010 7:57:06 AM

I game on a relatively small monitor (19 inch or so) and save money by moving my head closer to it ;)  . However, I do like to play games with *lots* of AA and AS. Resolution is already mentioned in the first post.

As for the PSU, thanks to Dell upgrading it is not an option, but the 5850 uses less power than the 3870x2, which my PSU will happily support through gaming and benchmarking without crashing or other issues.

From a little research, it seems that normally PSU companies rate their PSUs on the maximum output they can give, if not indefinitely, whereas Dell give the maximum wattage the PSU is guranteed to sustain indefinitely, hence giving abnormally low ratings.

EDIT: Regarding support, I won't make the same mistake again. Really should have got wise to it by now: on an old PC Dell shipped it with a faulty BIOS - lost the contents of the hard drive TWICE before their support deigned to mention it! Other Dell support highlights include telling us to leave the computer running low-level diagnostics - don't touch whatever you do - until he called back. Guess who never called back.
January 6, 2010 8:13:08 AM

Although HD5850 is an overkill for a 19 inch monitor but definitely is the best choice. Amongst all the cards available to you. If your PSU is able to sustain 425W then HD5850 is the one.

Dont worry, we all make mistakes in judgment sometimes. Even i bought my 1st PC which was a PIII, was full of mistakes in component selection. :kaola: 
January 6, 2010 8:29:40 AM

If your PSU can handle an HD3870x2 it can easily handle an HD5850 as it's quite low power.
I highly recommend a new monitor to go with your new card or just get something cheaper like an HD5770. Even a card half as powerful as an HD5850 is overkill for your current resolution. A decent 1920x1080 23-24" monitor will make a huge difference in your gaming experience and really isn't that expensive these days. If you do get one I guarantee the idea of going back to the other monitor will seem nearly unthinkable.
January 6, 2010 8:40:30 AM

Well, the way I see it, I can always plug in a new monitor (I know a friend who purchases unreasonably large screens and I might be able to get one of his older ones at a 'discount'), but if I get a cheap GPU I'm 'locked in', if you get my gist, if I still want good performance.