When I got my Leadtek card, I had the niggling feeling that maybe I should have overdrawn a bit more and got the DDR version, but it was an extra £50, so I chose against it. The card, even when overclocked gives gorgeous performance as shown in reviews - but being the type of person I am, I wanted to see exactly how fast I could overclock it!

When the card arrived, I was amazed at the truly pants heatsink and fan included on the chip, I've seen 486's with bigger fins! Even my TNT2 M64 had a decentish sized H/S on it. Seeing as this was what I had been supplied with, I thought I better see how efficient it was. After running Quake 3 for a while, the heatsink was bloody hot and so were the RAM chips. I also noted that the back of the board behind the chip was red hot and not cooled :( As regards overclocking, it's life expectancy is low enough as it is!

After raiding my box of heatsinks, I decided it was time to take some action. The heatsinks I used in this operation are two 486 heatsinks, about 7.5mm high (about the same as the original on the card) and a P75 H/S about 25mm high. The picture to the left compares the original h/s with the P75 one I replaced it with.

The first thing I did was to detach to original H/S and fan from the core, this can be done with a pair of needlenose pliers on the back of the board, but in my opinion this is a bit difficult and one slip can ruin everything. Instead I took a pair of side-cutters and snipped it off from the front side letting the heatsink just fall off and reveal a very small amount of heatsink cement and a naked core.

I could see there where four small holes which where smaller or two holes slightly larger that the original H/S used. I decided to go for the two hole option which meant a heatsink at an angle. If you have an old retail Celeron H/S fan lying around, that might do a good job and not need to be at an angle.

I drilled a hole in each corner so that I could attach it through the holes on the board. I then lapped the H/S for the best contact possible. Next I looked around in my spare nut and bolt jar to find a pair that fitted through the holes. If you have to buy some, get nylon to prevent shorting out the board. I used metal bolts with rubber washers to prevent contact.


I applied a bit of heatsink paste to the core and bolted on the heatsink. I had to file off the corners to prevent it hitting a component. I then used a 486 fan to cool it, but for more efficient cooling you can use a pentium fan (which I found later and used in my testing).

The next stage was to cool the RAM chips, this is very tedious and for a lot of you probably not worth it. I cut the two 486 H/S's I had into a total of 16 pieces, one for each chip - this took ages. Remember don't do any hacksawing any where near your computer because those little filings can kill components. I used super glue to attach them as it's quite a good heat conductor, but frag tape and Artic Silver Epoxy will do the job as well. Here is what my finished outcome looked like.



Pretty meaty looking don't you think?

How well does it overclock?

Let's see some benchmarks!





Benchmarks

Okay, now for some benchmarks. I used Quake 3 Arena TimeDemo Demo001 as a benchmark.

The Test Bed

Windows 2000 Professional
Dual Celeron 400@550 (92mhz bus * 6)
128mb RAM @CAS2
Leadtek Geforce 256 SDR with AGP at 1/1 divider (therefore overbussed at 92mhz instead of 66mhz)

NB: SMP MODE WAS NOT ENABLED IN QUAKE 3.

I used the following Quake 3 Configuration:
Nvidia Reference Drivers 3.81.
1152x864
Trilinear Filtering
Lightmap lighting e.t.c
3/4 Texture detail

Core Speed	Memory Speed	FPS	Performance Increase
120	166	28.5	0%
155	166	29.3	2.8%
120	190	32.6	14.4%
155	190	33.7	18.2%

I find the results quite surprising, I thought the core increase would make more of an increase to the Geforce performance as I was hoping to go higher. It seems it's the memory speed that made the big difference which is why the DDR cards are better. Although doing this modification to my Geforce did not necessarily give the performance increase I was after - it leaves me happy feeling it's running cooler.

As far as providing extra overclocking, my particular venture did not quite give the performance I was after as I have heard of people getting similar or equivalent out of the box. Hacksawing 16 little heatsinks is tedious but efficient.If I was to recommend this to someone I would say, buy a BIG heatsink (eg one designed for a processor 400+mhz) and do a better job than I did.

I still had a feeling I wasn't quite finished with my venture so I found a big mains powered fan which I took out of a broken microwave which had a HUGE blow on it - I then sat it right next to the card so the chips where running very cool to the touch. Surprsingly, although I managed to get the core more stable at 160mhz (which I was very close to before) the memory overclocked no more. I put down the lack of overclocking basically to the card. The problem with even attempting to cool, let alone super cool the memory chips is the fact there are so many! So good luck to anyone who attempts this, and tell me how you do. Although there are kits available, it will cost a lot less to do like I do!

Spode