HD4850 + Thermalright V2 (now with extra volts!)

I decided to quickly do some testing with extra volts before i retire this card.

I bumped the gpu up to 1.33v and went for gold. I managed stable clocks (3dmark, crysis, cod4) at 850mhz on the core. This was only 40mhz lower than with watercooling at the same voltage. Temps only just hit the sixties (full load) even with such high clocks and overvolted. This really says something about the quality of the heatsink.

Anyway, here's the usual screenie to justify my rambling above.


I'd recommend this little bugger for anyone who wants to do some overclocking on the cheap.

Mini Review: Thermalright V2 VGA Cooler (on a HD4850!)

After butchering the heat sink on my poor old HD4850 with an angle grinder (long story...), i needed a new, cheap and effective way of cooling this card. After browsing through the usual online stores, i stumbles across the Thermalright V2 copper heat sink at PCCG for $27. Considering most (ie more recent) coolers were around the $60 mark, i thought it looked like a great little buy. I didn't need maximum performance, just something to replace the already lacking stock cooler.

Here's a shot of the typical Thermalright packaging. Plain old cardboard. Just the way i like it, no rice, just performance!


Here's the bundle of goodies hidden away inside. We have the heat sink, instructions, ram sinks (hah, if you can call them that!), thermal paste, mounting hardware and of course, the trademark crappy Thermalright sticker!


Here's a closer look at the heat sink. Pretty standard all copper design with 4 heatpipes. Nothing new here, it just looks like a low profile version of the old XP-90C.


A shot of the base. A little bit grubby, doesn't bother me all that much. All the people that require A++ mirror finishes from the factory will not be impressed though.


Ahh the 'ram sinks'...... Just look at the size of this thing. IT'S ONLY JUST BIGGER THAN A BLOODY FAN CONNECTOR. I think it might hinder performance if anything, but it was free... so it goes on!


Here's a shot with the ram sinks installed. You might notice there's two which are almost flat. This is because the heatpipes won't fit over the standard sized sinks. Again, it probably just heats the ram more. You might want to consider some kind of mosfet cooling at this point. You can see my heatsink which i used earlier with my watercooling.


The heatsink is mounted with 4 thumb screws on the back. Installation was very quick and easy. No crushed cores today *remembers mounting volcano 7's on 9700 cards*


Here's a shot of it installed. One positive of this heat sink is it's fairly low profile. There's plenty of room if you're running a crossfire/sli setup.


Now with a 80mm fan installed. This little Spire fan has been going strong for years!


Now to performance... I wasn't sure what to expect here as I'm very unfamiliar with any gpu heat sinks made in the last few years. I bought this on clearance so i wasn't going to rule out average/poor performance with such a new and toasty card.

The results? Great! Idle temps were down to 31 degrees where the stock hsf would hover around in the 60s. Under full load, temps only reached an amazing 44 degrees! This was an amazing 36 degrees lower under load than the stock heatsink! For $27 i was absolutely over the moon with the performance, not to mention almost dead silent operation.

So... the overclocking! I managed to reach 700mhz on the core with this cooler. That's a 33mhz improvement over the stock cooling. After overclocking max temps only reached 47 degrees under load. Again, i was very impressed with this result. I feel that the overclock was purely voltage limited after seeing how well it flew with extra volts under water. I'm not going to over volt it under air atm because this card is soon to be retired and hopefully going to a new loving home where the owner will overclock the s*** out of it!

Unleashing the 4850 Part 3 - Cooling and overclocking

Finally i will finish off my little HD4850 adventure. I was quick to wrap this up because i picked up some new hardware today and just couldn't wait to play.

Here's the naked card. We will need to add a heatsink to the mosfets on the right which is very important because these suckers get hot.


Here's the heatsink in question. I found it in the deep dark depths of my cupboard o' crap. I think it was an old P3 heatsink (half of one anyway).


Here's a shot of the bottom. The small step makes it a perfect fit for the card!


I installed it using thermal tape but due to its weight, i used a cable tie to ensure it doesn't fall off.


I had every intention of adding ramsinks, but unfortunately i didn't have any on hand that were suitable. The best ramsinks (imho) are made by chopping up any old gpu/cpu/nb/sb heatsinks and sticking them on with artic adhesive or thermal tape. Spending $30 for a pack of 8 pre made ramsinks is crazy. I know i can think of hundreds of better things to spend that on. Do not overvolt the ram without ram sinks. The ram gets very hot to touch even at stock settings, i do recommend overvolting with ramsinks and decent airflow.

I'll be using a Swiftech MCW60 waterblock to cool the gpu on this beast. Many prefer the option of the full cover waterblocks but nothing can match the simplicity and upgradability of the MCW60. I could argue all day why the full cover blocks are a waste of money... but i wont. Lets just get into some overclocking!

Unfotunately nearly all the pictures i took did not turn out. Photography isn't my strongest asset and most shots were taken over by the flash reflection. Here's one shot of the card in my rig with the waterblock installed. One thing to note is how simple reading the voltages becomes with the use of the molex connector. The test probe slots right in and there's no danger of shorting any components. As you can see, the VGPU mod is turned on (bottom) and the VDDR is in the off position.


The test setup:
E8400 @ 4ghz - Frozen SS
Gigabyte x48-DS4
Corsair 2x2gb PC2-8400 Dominators
Connect3D HD4850 - MCW60
74gb WD Raptor
Thermaltake 750watt Toughpower
Fluke Multimeter :)

I used 3DMark Vantage to test for max stable clocks without artifacts. Note that i only overclocked the memory to an even 1000mhz (stock 993mhz). This was due to not having any ramsinks installed and i didn't want to take the risk of damage.

Stock cooling and voltage (1.2v load) i only managed a pathetic 670mhz on the core. Any higher than this and i would get slight graphic corruption and experience crashing. Temps were well above 90 degrees load.

With a voltage bump (1.3v load) i was able to achieve a very respectable 890mhz on the core. I was very happy with this result for safe 24/7 gaming. Temperatures only hit around 43 degrees load which says excellent things about the MCW60.

I finally bumped the voltage again up to 1.4v (still, fairly safe under water) and managed an amazing run of Vantage at 975mhz on the core. This was not stable for 24/7 use however, but with a little extra voltage i'm sure i could have broken 1 ghz on the gpu.


Overall i'm extremely impressed with the 4850s performance and it's excellent response to voltage. Priced at only $200, these cards deliver exceptional results and are unmatchable in their price bracket. I would highly recommend voltmods for this card if you're after maximum performance and are keen to take the plunge into extreme overclocking territory.

Unleashing the 4850 Part 2 - Volt Modding

Now we're getting to the fun stuff. Volt modding is great way to get a cheap (free) jump in mhz. Often people are turned away by the thought of potentially damaging the gpu or reducing the life of the video card. In reality it is no different to overclocking and raising the vcore on a cpu. By raising the voltage in small increments and using the appropriate cooling, volt modding is perfectly safe and a great way to either truly push your video card to it's limits or just add some extra gaming performance.

You will need:
- Digital Multimeter. Do not perform any kind of volt mods without one of these.
- A low wattage soldering iron. A 15watt dick smith/jaycar cheapie will do the job. Make sure it has a nice sharp tip, otherwise it can get difficult in tight places.
- Some kind of wire cutters/strippers to make life a little easier.
- Small guage wire. Solid core is better for this stuff imho. I usually cut IDE cables into strips and use them. Perfect size for volt modding.
- A hot glue gun/double sided tape or alternative solution to mount components to pcb.
- Electrical tape (optional)
- 2 x 100k multiturn trimpots. Vertical or Horizontal. Used for adjusting voltage.
- 2 x 3pin fan headers - used for turning the mods on/off.
- 2 x jumpers from an old motherboard/hard drive. used with the 3pin header for on/off control.
- 1 x Molex connector for checking voltages


Now lets get started!

First up are the areas where the work needs to be done. Print these off before you take the video card out of your machine :).

This picture was borrowed from techpowerup. I didn't have a full shot of the rear yet.

VGPU - Solder 100k trimmer between this point and one of the grounds above.


VDDR - Solder a 100k trimpot between these two points.



Here's a picture of the VDDR mod completed. This enables you to raise the voltage to the RAM allowing extra memory speeds. Ramsinks are recommended when using this mod. I forgot to take pictures of the process but it is explained below in more detail for the VGPU mod.
I like to use regular 3pin fan headers combined with a standard motherboard jumper to turn the mod on/off. I have used this method for years and it's very effective if you do not want to run overclocked and overvoltage settings 24/7.

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Now we will move on to modding the GPU voltage (often reffered to as VGPU).
Here we are using a 100k trimpot. Either horizontal or vertical will work fine - i used vertical ones because that's what i had on hand :).
Here i have used double sided thermal tape to attach the trimmer to the pcb. I prefer using a small dab of hot glue but i wasn't able to locate the gun. I recommend cutting off the 3rd leg of the trimmer which is not required.

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Here is the trimmer attached to the pcb. Alway try to place it in a practical place which requires the least amount of wiring. Having them at the top edge of the pcb allows for easy adjustment and almost completely reduces the chance of shorting out components when rasing/lowering voltage.

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Like the VDDR mod, i like to use 3pin fan headers with jumpers to turn my mods on and off.

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I attached the fan header to the trimmer using more double sided tape. Again, i would recommend using a hot glue gun if you can stand the mess.
Here i have bent the middle pin of the trimmer up and soldered it to the middle pin of the fan header.

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Next we solder the pin from the fan header to ground. The other pin remains unused and you can remove it if you wish.

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Now attach a wire to the remaining leg of the trimmer ready to solder to the pcb. Remember to use heatshrink tubing over the connection to prevent any unwanted accidents.
Note: Don't use a lighter to shrink the tubing - cloth covered wire is quite flammable! I also managed to burn the wire. Poor form all-round.

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Lets solder the yellow wire to the pcb. Make sure you have a nice fine point on your soldering iron for this job, especially if you're new to soldering. The chisel point on my weller made it extremely difficult to do this. Remember - use the right tool for the job! Use some electrical tape as a bit of extra security to hold down the wire to the pcb to prevent it accidently catching on your finger while re-installing the cooler.

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Here's a picture of the VDDR and VGPU mods completed (and in the off position).
Hmm but how do we measure the voltage?

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Molex connectors are perfect for the job! Great size for a multimeter lead to sit safely inside. I used two test points on this one - one for VGPU and one for VDDR. It's generally a good idea to add another read point for GND, but it slipped my mind at the time.

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Here's a shot of the two read points. VDDR left and VGPU right.

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Here's a shot of all the mods completed.

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Next up i'll cover installing a waterblock and cooling the ram/mosfets.

Unleashing the 4850 Part 1 - A quick overview.

Hi guys,

With the recent launch of the new HD4800 series, AMD/ATI have taken the video card market by storm with two extremely powerful and great value cards. Seeing as nearly everyone has now adopted one of these babies, i thought it would be good to throw together a quick guide to getting the most out of them.

I currently own two HD4850s which are successfully running in crossfire. This guide will focus primarily on the 4850 where we will take a look at the stock cooling, volt modding, and conquering the heat.

First up... Some inspirational music... :)
It's been scientifically proven that listening to Nevermore automatically adds 100mhz + to your maximum overclock... something like that...

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Here's a look at the 4850 working hard in my rig. We can all see the obvious design flaw here - a single slot cooler! Hopefully the name brands will have custom solutions out soon enough.

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After taking the hsf off the 4850, we can tear her apart and have a closer look.

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This is whats under the red plastic. Notice how the fins are covered to create a wind tunnel. Also note the sad size of the fan. It's a noisy little bugger at high speed and can be a real pain if you have an open rig without a case. I do like the mosfet cooling however - we will be recycling this later when we move to water.

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A shot of the underside of the heatsink. Standard mounting holes which will make fitting aftermarket heatsinks and waterblocks a breeze. However all the folks that like their full cover waterblocks will need to buy a new one which is compatible with the 4850.

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Here's a closer look at the fin design. ATI really should have opted for some kind of dual slot cooler on this one. Some users are reporting load temperatures of 100 degrees or more. Personally i have found that after installing a 120mm low rpm fan over the two cards, i managed to receive load temperatures of around 60 degrees which is quite acceptable by anyones standards.

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Now we can take a look at the card in all its naked glory.

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Hmmm better clean that gpu... ahhh metho!


All cleaned up :)
Pretty huh?

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A closer look. This little baby puts out more than her fair share of heat.

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I think you may have noticed by now that my photography is quite poor. Here's a final shot of the power section. The 4850 only uses 1 x 6pin pcie connector while the 4870 uses 2. The mosfets will really heat up when we start cranking the volts so we will have to cool these suckers too.

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That's all for now. Hopefully we're all a little more familiar with the card and we can move on to some volt modding.