Introduction

For most folks the reason for buying a new video card is simple necessity, either the old hardware broke, or is in need of an upgrade. Than there are those who upgrade every few months to the latest and greatest in order to run their games and insanely high resolutions and quality settings. It should come as no surprise that the number of people who upgrade this often is quite small compared to the occasional PC user. Than there’s a third kind of people, who upgrade and buy new hardware, not because their PCs are too slow, not because it broke, and not because they want to run the latest games and applications at high speed. These people buy hardware just to run benchmarks and posts scores in popular forums and on World Record databases. There are not a lot of these people around; they are in the top echelon of the aforementioned category. Still they do thrive and gain number each year, these people tend to get early samples of new hardware and share them with their fellow enthusiasts.

Today we bring you our very own in-house report on this strange breed of PC users who’s only goal of buying a new hardware piece, is to run benchmarks over and over again to get the highest scores. In cooperation with the enthusiast Belgian Overclocking Team we gathered up 20 samples of an affordable VGA card to organize a “VGA Overclocking Contest”.

While it would be cool and interesting to get every participant to cough up €500+ for this contest, we thought we would have more success if we kept the price of the VGA card below the €100 mark. Since this is an overclocking contest, it would be no good to get a video card which doesn’t really scale well with higher clock speed. We started our search at the beginning of the year, with promises of NVIDIA low-mid range video cards in the coming months we tried to get prices for the 8400/8500 series; unfortunately, NVIDIA failed to actually improve performance over their last generation cards AND the last 7 series were cheaper too. We checked results for different video cards at forums and websites, but in the end found the answer at HWbot.org, this hardware database keeps records of over 60.000 overclocking results with different hardware. We used their nifty auto chart generation tool and gathered up a series of <€100 cards. We were interested in the average overclock and found this at the bottom of the charts page:


Source: HWbot Performance Charts

We even included the Geforce 6 series in our search, as the 6600 GT had proved popular in the past, but in the end it was the newer 7300 GT DDR3 (the DDR2 version is not quite the same) we choose to go for. With an average overclock on the GPU of ~35% we started looking for good deal on this PCI Express card. For an attractive €70 we got the units to ship to our participants, the samples were Zotac 7300 GT 128Mb DDR3 PCI Express, from Tecnacom



Zotac 7300 GT in the house!

The Geforce 7300 GT GPU is low end, there is no doubt about that, in our recent 7300 GT vs 8500 GT shootout we got most games to run at 1024x768 with medium detail. We rounded up 20 samples and shipped them to different hardware crazy folk:



Setting up a contest and benchmark rules

Since this is a VGA overclocking contest and we know most benchmarks are influenced greatly by a faster CPU and/or memory we decided to really tip the balance to put stress on the video card. With help of Futuremark we got our contestants a registered copy of 3DMark2001SE and 3DMark03.



Are you wondering the 2001 and 03 stand for the year the benchmark was released? Yes that’s correct. But that means these benchmarks are seven and four years old! The advantage of these older benchmarks is that they don’t have clue about multi core CPUs and don’t take advantage of this, thus we focus on VGA power to make the difference. To further stress this point we demand the contestants to run both 3DMark benchmarks at 1280x1024 resolution, and only take into account the score received from the “Nature” sub-test. (for a full set of rules please check this page)


Although the benchmarks themselves are dated, Futuremark has always been ahead of the gaming industry in the “bells and whistles” department, both Nature Tests are from from ugly compared to today’s game engines.

So the players have entered the ring, the rules have been set, the video card chosen and delivered, time to start the overclocking engines. On the following pages you can find updated work logs of the different 7300 GT overclocks, featuring custom cooling modification, voltage modding, sub zero chilling, windows tweaks, driver version deviations, GPU scaling, memory OC’ing and much more. If you want to find out how to get the most out of your budget video card, we’re sure you’ll find some useful info in these work logs.

Page2: Gamer’s 7300 GT ~ Subzero, Hyper TX, voltmods

Page3: Troman's 7300 GT ~ Alu/Copper HSF, voltmods, capacitor moving, dry ice

…. More to come, check back regularly!

Gamer’s Worklog

We start of our worklog action with a geek who’s basically doing the exact opposite of what his nickname makes you believe : Gamer. Although he’s no longer in his twenties he hangs out with the “young crowd” everyday. His primary workstation is a Core 2 powered laptop with 7950GT powered VGA card. So he fits the bill of the hardware geek completely when he decided to buy €1000+ of new material to test a €70 VGA card! (That’s excluding the phase change cooling unit!)

His collection of hardware acquired to do nothing but run benchmarks include two Core 2 Duo CPUs (E6600/E6300), two Asus motherboards (P5B, and new P5K), some OCZ 2x1Gb VX2 memory modules, a 700W high end Zippy PSU and to finish the job off a blistering fast 40Gb 5400rpm HDD from Maxtor ;)

After installing his favourite Windows OS he got right down to business, the 7300 GT from Zotac is clocked by default at 500Mhz for the GPU and 750Mhz for the memory, using stock cooling Gamer pushed his card up to 690/850 for his first 3Dmark2001SE benchmark runs.

His setup is what most benchmarkers (if there exists such a word) use, an open test bed with lots of drivers CDs and cables bundled up in a cosy mess.



With a bit more tweaking and fiddling with driver versions his first score submitted for the 3DMark2001SE ranking was 189.9FPS in the “Nature” Game test. With default video card clock speeds you get ~135FPS on average at 1280x1024 resolution. With clock speeds increased to 680/961 as Gamer did you boost performance by ~40%! Impressive to say the least.



Wait a minute there; in the 3rd paragraph we mentioned his maximum GPU clocks at 690, why only 680Mhz is shown here. Turns out that pushing the GPU past its maximum “stable” speed doesn’t cause an immediate crash, the increase “faults” cause the 3D performance to decrease, so clocking the GPU lower actually makes the score go up!

At this point in the contest most people had their cards running on air cooling at GPU speeds between 660 and 700Mhz, thus the final scores were not very far apart, software tweaks only helped “that” much and they were hungering for more GPU power. Scanning search results of different Google queries didn’t make us any wiser on how to increase the voltage to either GPU or memory chips. In the end it was our very own Geoffrey who figured it out and graciously provided instructions to everybody (he could have kept it for himself, but where’s the fun in that) on how to do the voltage modification.

Gamer was the first to pick up a pencil and strike it a few times over the correct resistors on the card, increasing the GPU & MEM voltage a bit. The end result for his effort was an increase in stable overclock to 710/1000, his 3DMark2001SE bumped to 196.6FPS, +45% over default. It was not enough for Gamer, so he decided to do, what people in the “business” call, a hard-mod. Finding the correct VR (voltage regulators) and using his trusty multi-meter he typed the following words in the forum:

Gamer: Can somebody voltmod this card for me?

When he didn’t get a positive answer in the next 24 hours, he did what any enthusiast would do, try it himself. He decided to do the GPU volt mod first, with a 10 Kohm 3-pin VR he wanted to connect pin 1 (or 3) the correct point on the card, the middle pint went to the ground connection. Friendly forum OC friend Massman advised him to take some useful safety measurements first:

Turn the VR to one side until you hear a click, this means you reached maximum resistance.

Measure the resistance between Pin1 and Pin2 and Pin3 and Pin2 n of the VR. One result will give you 0 ohm, the other 10k ohm.

If pin1 and pin2 gave you the 10k ohm readout, solder pin1 to the correct bridge of the chip on the video card, and solder pin2 to the GND (ground). If pin3 and pin1 give you 10k ohm, solder pin3 to the correct place on the card.

Now measure the voltage read-out from the card with your multimeter

start turning the VR slowly and keep eye on volts and temperatures

Half an hour after he got this explanation from Massman, he couldn’t quite get it figured out, as his VR had one pin up and two down – he measured 0.40k ohm between pin1 and pin2 and didn’t know exactly what to do next. So Massman drew up this nifty chart in MSpaint:



Massman added: “If you only measured 0.4 kOhm resistance between pin1 and pin2 you shouldn’t solder those pins, otherwise you’ll burn the card”. Thus gamer had to use pin2 and pin3, pin3 leading towards the video card.

With this explanation Gamer quickly got the hang of it and soldered the VR to the correct places and booted up the machine with the new and improved 7300 GT. He discovered that turning the VR, ever so lightly, boosted the voltage quickly, he was at 1.8v quickly. The hard mod paid off, his highest GPU clock went up to 854Mhz and memory boosted alongside thanks to more pencil mod action to 1023Mhz. His 3DMark2001SE score, a massive 226.2FPS, 67% over stock speed!


This overclock was achieved with the stock cooling of the Zotac card, which is quite impressive!

It went quiet in Gamer’s worklog for a few weeks but then he posted again, one compare link to a 3Dmark2001SE score of 256.4FPS (89% OC over stock!) and leaving us guessing at how he achieved it, and at what speeds. We assumed correctly when we though sub zero cooling, finding out the GPU clocks was not too difficult as he had mentioned them in the FM compare link; 950Mhz on the GPU and 1060Mhz for the memory! He had increase volts to the GPU to 1.85v to achieve this goal.



He not only sub zero cooled the video card, but the CPU too, although the contest limits CPU speeds for Core 2 Duo to 3Ghz, he wanted more CPU power for HWbot.org ready scores.

Since the VGA Contest is ranked in categories, his 256FPS score stands alone in the chart; the overclocking on air ranking has more competition. His 226.2FPS held first place for a while. Until Troman Pardons entered the game. His worklog will be posted at the site tomorrow.

Troman’s Worklog

You can’t have a competition amongst friends without some teasing and taunting. Troman this down to an art, about half his posts in his worklog are hint towards the others to prepare for a defeat in the contest. Time to put his money where is mouth is we said.

He started of slowly by posting his first score with an Athlon 64 system, running at default speeds and few driver/setting tweaks he reached 139.5FPS in 3DMark2001SE’s nature test at 1280x1024:



Of to a slow start with the video card running at stock speeds, but that did not last long, the first overclock with stock cooling pushed the core to 648Mhz and memory to 840Mhz which gave a nice boost to 176.2FPS:



When he figured out the voltage mods for the GPU he increased them to unhealthy levels and was faced with an overheating GPU. So on to the cooling modifications. He first used an older Athlon 64 aluminum heatsink, but with the GPU reaching ~69°C when under load, GPU stability became an issue, he topped out at 820Mhz core, which landed him at 217.7FPS, a very high score indeed:



Without leaving the air cooling category he searched his hardware collection for an appropriate heatsink, a large copper heatsink was his next cooling installed on the card. For this to work he actually moved some of the capacitors which are normally at the front of the 7300 GT card, to the back, so the copper heatsink could be mounted:



Coupled with some high output fans the cooling power definitely increased




At 1.88v GPU voltage the GPU temperature was only ~49°C, quite a nice drop, and it enabled him to push the GPU core to 883Mhz, in the meantime he also did the memory volt mod allowing another boost there to 1010Mhz. The end result is close to a 100FPS boost from stock speed, 235.9FPS



A few more tweaks and higher clock speeds allow Pardons/Troman to grab first place (for now) in the air cooled ranking, with an impressive 236.3FPS score at 884/1024 speeds.

As was the case with Gamer, subzero cooling can be quite effective when pushing beyond the normal speed limits of hardware; Troman decided to modify the cooling on the 7300 GT for Dry Ice (a guide on how to work with dry ice you can find here). The 7300 GT card is dwarfed by the cooling tube:




Gamer’s phase-change cooling allowed him to push the GPU to 950Mhz, after a successful Dry Ice session Troman got the GPU core up to 960Mhz using 1.85v on the GPU and 2.45v on the mem, good for 1054Mhz. In order to get this high he did mentioned he had to increase the PCI Express speed to at least 125Mhz. Sadly enough when he tried to upload his results for this Dry Ice run after swapping out the 7300GT with a more modest, passive cooled, 6200LE NVIDIA card, the Windows OS gave up, spilling out I/O errors and forcing him to do a reinstall. While Troman at this point in time has no official subzero score published, he showed us what’s possible, maybe enough to beat Gamer’s top score.

Stay tuned for our next worklog update, this time by Geoffrey who delved into the GPU speed scaling side of things!