From his start as a teenager building PCs for students and faculty at a college in his hometown of Raleigh, North Carolina, he's become one of the semiconductor industry's most closely watched reviewers. His website, AnandTech.com, is all about product performance, plain and simple.
Shimpi measures exactly how fast the latest Intel processor really is, how quickly that graphics chip will render the latest video game, how long that laptop battery will last.
At age 30, Shimpi is courted by technology executives and followed by Wall Street analysts keen to hear his well-informed product views. He briefs Intel executives, dines with Asian PC executives and commands a loyal following of tech enthusiasts, with AnandTech.com drawing 12 million unique visitors per month.
His workbench at his home in Raleigh is cluttered with high-end storage drives, laptops and recently released tablets, one of them playing a Harry Potter movie in an endless loop. A storage room is filled with hundreds of other products shipped to him over the years, and he says UPS drops more gear off almost every day.
"All of this is used in one form or another," Shimpi says, gesturing toward the stacks of equipment.
Poor marks in one of his so-called benchmark reviews, focusing strictly on performance data, can mean trouble for a new product.
And because Shimpi amasses performance data on a wide range of chips and other products, he sometimes has more insight in certain areas than companies' own design engineers, said Alex Mei, chief marketing officer for enterprise storage vendor OCZ Technology .
"His criticism carries more weight," said Mei. "He really has a bead on what his readers are looking for."
Indeed, OCZ altered the design of a solid-state drive a couple years ago to take into account Shimpi's suggestions about how customers would likely use the product.
AnandTech is not alone in the benchmark review business; sites including The Tech Report and Tom's Hardware have a similar obsession with performance data, though smaller followings.
But many chip executives, Wall Street investors and technically minded consumers see Shimpi's meticulously collected test results as the most authoritative and highly trustable.
Dozens of widely read blogs write more subjective - and often more easily digestible - reviews of laptops, phones and tablets based to a large degree on how much the reviewer likes the product. Increasingly, those reviewers conduct limited tests of their own, using "off the shelf" benchmark tools.
Still others make mention of Shimpi's data, painstakingly collected using proprietary tests he has developed over the years.
"We have known Anand for a long time," Jonney Shih, chairman of the big Taiwanese computer-maker Asus, told Reuters by email. "We definitely share a passion for technology and we respect his in-depth knowledge and the thorough testing that he does."
Hobbyists go pro
Today, reviewers are turning to benchmark tests to evaluate the chips, touch screens and batteries in the latest tablets and smarpthones, a fast-growing market in which Apple , Samsung, Intel, Qualcomm and others are competing fiercely.
But the niche business made its mark during the personal computer boom of the 1990s, when chipmakers fought for bragging rights about everything from clock speeds to latency.
Developing scientific ways to verify manufacturers' claims and compare the performance of motherboards, processors and other components became a hobby among a small group of tech enthusiasts.
Data was compiled in reviews and posted on websites where they were read by legions of other technophiles, who in turn have become an important target for tech industry marketers.
"They're the decision makers, influencers, guys who work in IT jobs during the day and play games at night, that people go to for advice when they have questions about technology," Chris Angelini, who started reviewing PC parts while at college and is now editor of Tom's Hardware, said of his readers.
As they gained attention in the industry, the benchmark reviewers grew more sophisticated - and attracted yet more attention from industry watchers.
Stock analysts, for one, have come to rely on the data when projecting product sales.
"We don't have tools to go out and measure these things ourselves, so we depend on independent third parties to take the devices and tell us things like what does the performance look like and how does it stack up relative to the competition," said Shawn Webster, a chip analyst at Macquarie.
This year, stock analysts have cited AnandTech measurements in more than 70 reports about Intel, Nvidia and other chipmakers.
With AnandTech attracting a large, specialized audience of cutting edge techies, it has plenty of advertising. The website has more than a dozen reviewers and editors, and has done well enough to make Shimpi a wealthy man.
The rise of smartphones and tablets has presented some new challenges to performance testers, but those devices have also created demand for more reviews. Shimpi believes he can continue to prosper by sticking to a simple mantra.
"What are they not telling me?" he regularly asks, referring to the companies whose devices he tests.
Shimpi recently demonstrated how he works, running scripted videogame sequences on a MacBook Air to test the performance of its graphics chip. That's just one example of several tests he runs on each device he reviews. The Harry Potter movie playing over and over on a Google Nexus 7 tablet was part of a test to document its battery life.
Shimpi carries out measurements several times for each device, with the results feeding spreadsheets with thousands of data points. It's a never-ending process as Shimpi adds new products to his database and runs new benchmarks on older ones.
Chip executives have embraced the most professional of the benchmark reviewers and ship them samples of their new products, often ahead of their release. In return, they get objective feedback.
"We literally go into every review site in the world we can find, and our teams read the reviews, and they decide internally whether it was a good review for us or a good review for the competition," Jen-Hsun Huang, chief executive of chipmaker Nvidia , told investors at a conference in May.
To make sure his reviews are ready in time for product launches, Shimpi pulls all-nighters and lays out his testing gear in hotel rooms during his frequent travels.
"If you put in an honest seven days of work - I'm not saying eight hours a day or less, I'm saying if you don't sleep for a couple of nights, and that's all you live and breath and do - I think it's possible to deliver a good review within that seven-day period," Shimpi said.
"Anything less and you start making sacrifices."
Evaluating PC processors is a matter of connecting them to one of the motherboards on Shimpi's table and running standard tests established over a decade ago. Testing the components in a mobile device like an iPad is trickier because it cannot easily be opened up and tinkered with.
To adapt, reviewers are resorting to some decidedly low-tech tools like stopwatches and cameras to measure the quality of tablet displays, how quickly web pages load, and battery life.
Soon after his start in high school building PCs for students and faculty at Saint Augustine's College in Raleigh, where his father taught computer science, Shimpi created a website and started writing about components. He quickly gained a following with a rapidly growing niche of PC enthusiasts.
"I would build the PC for free and then say I want to review this stuff before I give you your computer," Shimpi said. "As I got popular, a couple of resellers wanted to put ads on my site. So I gave them ad spots in return for more hardware to review."
As the website grew, Shimpi started getting invitations to visit with companies and attend trade shows. Self-conscious about his age, he wore suits to meetings.
AnandTech soon made the teenager financially independent. He went on to study computer engineering at North Carolina State University while continuing to build his business.
Today he stills wears a suit to meetings and trade shows - sometimes accompanied by sneakers. He deliberately maintains a distance between his personal life and the tech world, even if that means frequent, long flights to Silicon Valley to visit chip execs.
His sprawling house, which he had built, includes a storage room for the parts companies have sent him over the years. It also includes a professional-quality home theater, carefully designed with the help of a reader and controlled by a computer Shimpi cobbled together for the task.
Plastic guitars and drums - the virtual instruments of the Rock Band videogame - are strewn across a sofa but Shimpi complains that he and his girlfriend, a sculptor who lives with him, are too busy to play much.
He takes phone calls from investors who pay him for his advice and spends more and more time hunkered down with design engineers. But Shimpi says his main focus will remain AnandTech's readers - the sort of tech fans who spend hours reading up on new products before deciding which to buy.
"I don't care so much how this affects the companies," Shimpi said. "They're going to be okay. It's the guy putting $200 down that he worked really hard for, and some guy he's never met is telling him he should do that. They're the reason I get to do this."
Copyright Thomson Reuters 2012