400W PSU & HD 7770 - Am I safe?

[bosing]

Hello. I'm considering one of these new HD 7770s, but feel a little uneasy with my current PSU.

My PSU: OCZ 400W Stealthxstream PSU

What's in the machine: i3, Gigabyte GA-Z68AP motherboard, 8GB of Corsair Vengeance RAM, two SATA hard drives, an Optical Drive CD/DVD reader/burner, (would I factor case fans too?).

I made a thread a couple of days ago seeking advice about this PSU paired up with a HD 6850. What's spurring me to continue with this PSU, is that I had specced an AMD CPU-build in that thread, not realising that Intel aren't as power hungry, and around the same price at my entry level. Regardless, opinion throughout the thread was a little mixed, which has stopped me in my tracks with an order.

If my components are safe when we go to boot up, I honestly don't mind paying the extra £20 ($30) for the 7770, even if 6800 series is superior.

Any thoughts, or advice that you might have would be very welcome.

All the best.

 

[purple stain]

That PSU should be fine,even a 6870.

Review:
http://www.hardwaresecrets.com/article/OCZ-StealthXStream-400-W-Power-Supply-Review/794/10

 

[bosing]

That PSU should be fine,even a 6870.

Review:
http://www.hardwaresecrets.com/article/OCZ-StealthXStream-400-W-Power-Supply-Review/794/10

Happy days. Can't say I knew what I should've been looking out for here, but this review does appear to vein in the positive.

Any thoughts about overclocking the 7770 & if my PSU can handle that? I honestly don't know if they're both explicitly relative, as I've never overclocked before.

 

[17seconds]

You might be a little light with only 400 watts:
http://www.guru3d.com/article/amd-radeon-hd-7750-and-7770-review/7

 

[bosing]

You might be a little light with only 400 watts:
http://www.guru3d.com/article/amd-radeon-hd-7750-and-7770-review/7

Thanks for throwing that link over.

Do you mean I'd struggle to power this card, never mind the overclocking?

 

[17seconds]

Thanks for throwing that link over.

Do you mean I'd struggle to power this card, never mind the overclocking?

You will probably be able to run the card on that power supply, but don't expect to overclock and have a bunch of drives and fans going, etc.

 

[bosing]

You will probably be able to run the card on that power supply, but don't expect to overclock and have a bunch of drives and fans going, etc.

Ah, OK. Yeah, reading further through Stank's link (the PSU review), it looks like the maximum I can draw from my PSU is along the lines of 450W. The OC was a little indulgent for me to consider, but I was curious. I'm only gaming at 1280x1024 anyway, so this card will hopefully pull enough weight for me in the meantime (right now, I'm running Skyrim on an 8800GT -- the horror!).

Thanks for your help.

 

[17seconds]

That Guru3d article explains that their system is heavily overclocked with all the power saving features turned off, so their power usage is well above the average user.

 

[Guest]

Ah, OK. Yeah, reading further through Stank's link (the PSU review), it looks like the maximum I can draw from my PSU is along the lines of 450W. The OC was a little indulgent for me to consider, but I was curious. I'm only gaming at 1280x1024 anyway, so this card will hopefully pull enough weight for me in the meantime (right now, I'm running Skyrim on an 8800GT -- the horror!).

Thanks for your help.

At that resolution a 6670 would probably suffice.

 

[andrewcarr]

You should be able to overclock the card with that PSU.
http://extreme.outervision.com/psucalculatorlite.jsp

 

[purple stain]

I don't see a problem with O.C.ing the 7770 on that PSU.The i3 only consumes 65watts.

 

[DM186]

Here to make it short and sweet. Look on the PSU and get the amps that are on the 12v rail/rails. They have to be 20 amps or higher. Your card only draws 86w and the system draws a total of 231w.

So you have to have 20amps or higher. To be right on it is 19.25 but you have to run fan's. If the amps are less then 19 then you have to get a new PSU. The only reason I said this is because you have one of the good PSU's

So by checking you will know for sure if that PSU will work or not. This should save a battle over the PSU.

 

[bosing]

Here to make it short and sweet. Look on the PSU and get the amps that are on the 12v rail/rails. They have to be 20 amps or higher. Your card only draws 86w and the system draws a total of 231w.

So you have to have 20amps or higher. To be right on it is 19.25 but you have to run fan's. If the amps are less then 19 then you have to get a new PSU. The only reason I said this is because you have one of the good PSU's

So by checking you will know for sure if that PSU will work or not. This should save a battle over the PSU.

Hey, the sticker on the box reads:


[cpp]AC Input 100-240Vac 5.0/2.5A 50 / 60Hz
DC Output +3.3V | +5V | +12V1 | +12V2 | -12V | +5VSB
Max Output Current .24A | 15A | 17A | 14A | 0.3A | 3.0A |
Max Combined Power 120W | 372W | 3.6W | 15.0W
Total Power 400W[/cpp]

If I understand correctly, the +12V1 rail(s) carries 17A, and the +12V2 rail(s) carries 14A, which makes a total of 31A (17 + 14 = 31). Am I on the right track?

 

[bosing]

You should be able to overclock the card with that PSU.
http://extreme.outervision.com/psucalculatorlite.jsp

I tried the calculator with the HD 6850 plugged in, and I still had about 85+W of headroom. Good news, thanks for the link.

 

[delluser1]

I tried the calculator with the HD 6850 plugged in, and I still had about 85+W of headroom. Good news, thanks for the link.

The psu calculator is giving you a psu wattage reccomendation, not power consumption , you will have much more than 85+ watts of headroom

 

[bosing]

The psu calculator is giving you a psu wattage reccomendation, not power consumption , you will have much more than 85+ watts of headroom

Ah, of course. Even better - looks like I'm set OK for the 7770. I might even consider a 6850 if they're still running cheaper.

 

[elbert]

Don't consider the 6850 or 7770. Go for the 7850 around March 6th. Power draw for the 7850 should be less than the 6850 but performance possible better than the 6950.

 

[bosing]

Don't consider the 6850 or 7770. Go for the 7850 around March 6th. Power draw for the 7850 should be less than the 6850 but performance possible better than the 6950.

Hey, yeah that might be a good shout, as pay day for me isn't until March 12th. It really depends on the price, with the 7770 already being a little expensive for my tastes. As said, I'm only gaming at 1280x1024, and I've read that most cards nowadays will breeze that resolution - most reviews aren't even bothering with benchmarks at my tiny screen size. I've no room to upgrade as of yet, and I won't be shifting out of this wee apartment any time soon.

Could be a good case of future proofing though.

 

[elbert]

Hey, yeah that might be a good shout, as pay day for me isn't until March 12th. It really depends on the price, with the 7770 already being a little expensive for my tastes. As said, I'm only gaming at 1280x1024, and I've read that most cards nowadays will breeze that resolution - most reviews aren't even bothering with benchmarks at my tiny screen size. I've no room to upgrade as of yet, and I won't be shifting out of this wee apartment any time soon.

Could be a good case of future proofing though.

The big thing here is the 7850 has double Stream processors, Texture Units, and ROPs of the 7770 for only $50 more. The 7850 may be twice as powerful as the 7770. If AMD doesn't change prices the 7850 should be the best bang for the buck. You end up with the 6850 being better performance value to 7770's dx 11.1. The 7850 tho has best of both worlds.

 

[Guest]

The big thing here is the 7850 has double Stream processors, Texture Units, and ROPs of the 7770 for only $50 more. The 7850 may be twice as powerful as the 7770. If AMD doesn't change prices the 7850 should be the best bang for the buck. You end up with the 6850 being better performance value to 7770's dx 11.1. The 7850 tho has best of both worlds.

the 7770 is priced $40-50 too high.

 

[purple stain]

Yeah AMD is making the prices really high right now cause they have no competition from Nvidia.Once Nvidia release's it's lineup prices will probably drop.

 

[DM186]

Hey, the sticker on the box reads:


[cpp]AC Input 100-240Vac 5.0/2.5A 50 / 60Hz
DC Output +3.3V | +5V | +12V1 | +12V2 | -12V | +5VSB
Max Output Current .24A | 15A | 17A | 14A | 0.3A | 3.0A |
Max Combined Power 120W | 372W | 3.6W | 15.0W
Total Power 400W[/cpp]

If I understand correctly, the +12V1 rail(s) carries 17A, and the +12V2 rail(s) carries 14A, which makes a total of 31A (17 + 14 = 31). Am I on the right track?

You learn fast and everybody else is right on the money. It pays to have a nice PSU on board. Good luck to ya.

 

[elbert]

the 7770 is priced $40-50 too high.

Yes as the 7850 is only about $50 more and should by specs be twice as fast.

 

[bosing]

The big thing here is the 7850 has double Stream processors, Texture Units, and ROPs of the 7770 for only $50 more. The 7850 may be twice as powerful as the 7770. If AMD doesn't change prices the 7850 should be the best bang for the buck. You end up with the 6850 being better performance value to 7770's dx 11.1. The 7850 tho has best of both worlds.

Yeah, if I'm spending that amount of money anyway, 50 bucks (or 30 quid in my case) isn't going to break the bank, especially when the performance on the 7850, is like you said, to be doubled in comparison with the 7770. But, if I'm strapped for cash and go with the 7770, I've read that their CrossFire performance is relatively neat, should I need an upgrade further down the line - surely in 18 months time, nabbing another wouldn't hurt the wallet too much.

Now that I'm crawling out of my Athlon days, I am finding the price & performance market a little more challenging - probably to do with my head being under the sand for so long. For an extra couple of bucks it seems there's always something much better around the corner. It pays to know what you want to get out of your rig, probably more so than ever.

You learn fast and everybody else is right on the money. It pays to have a nice PSU on board. Good luck to ya.

That's great, thanks for your help.

 

[elbert]

Yeah, if I'm spending that amount of money anyway, 50 bucks (or 30 quid in my case) isn't going to break the bank, especially when the performance on the 7850, is like you said, to be doubled in comparison with the 7770. But, if I'm strapped for cash and go with the 7770, I've read that their CrossFire performance is relatively neat, should I need an upgrade further down the line - surely in 18 months time, nabbing another wouldn't hurt the wallet too much.

Now that I'm crawling out of my Athlon days, I am finding the price & performance market a little more challenging - probably to do with my head being under the sand for so long. For an extra couple of bucks it seems there's always something much better around the corner. It pays to know what you want to get out of your rig, probably more so than ever.



That's great, thanks for your help.

If you don't like the price I suggest you get the better bang for the buck 7750. It tends to perform equal to the 6770 and not to much below the 7770 for about a $50 savings. Video cards update about every year and in 18 months all 7000 series will be sold out and only 8000's will be in supply. Given that cycle you may be better off with the 7750 and get a 8750 in 18 months.