• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

PCI Express 3.0 Has Zero Performance Incentive for Radeon HD 7970: Tests

btarunr

Editor & Senior Moderator
Staff member
Joined
Oct 9, 2007
Messages
47,300 (7.53/day)
Location
Hyderabad, India
System Name RBMK-1000
Processor AMD Ryzen 7 5700G
Motherboard ASUS ROG Strix B450-E Gaming
Cooling DeepCool Gammax L240 V2
Memory 2x 8GB G.Skill Sniper X
Video Card(s) Palit GeForce RTX 2080 SUPER GameRock
Storage Western Digital Black NVMe 512GB
Display(s) BenQ 1440p 60 Hz 27-inch
Case Corsair Carbide 100R
Audio Device(s) ASUS SupremeFX S1220A
Power Supply Cooler Master MWE Gold 650W
Mouse ASUS ROG Strix Impact
Keyboard Gamdias Hermes E2
Software Windows 11 Pro
Over the last few months, motherboard manufacturers have been raising a big hoopla over how it's important to pick their products that feature PCI Express 3.0 (Gen 3.0) slots. There was even some drama between competing motherboard manufacturers over who was first to the market with this technology, even when consumers couldn't really make use of the technology. To begin with, you needed a next-generation Ivy Bridge CPU, then you needed a compliant graphics card. Sandy Bridge-E, fortunately, formally introduced the technology, complete with motherboards and processors that support it.

GPU maker AMD wanted to be the first to be out there with a GPU that's compliant with this interface, and so one thing led to another, and VR-Zone got to set up a test-bed using Core i7 "Sandy Bridge-E", ASUS Rampage IV Extreme (which allows users to change PCI-Express standard mode in the BIOS setup program, by forcing Gen 2 or Gen 1 mode), and an HD 7970, to see if running the GPU on PCIe 2.0 and PCIe 3.0 modes made any worthwhile difference. The results are in: zero, nada, zilch, sunna (zero in my language).



In its comparison, VR-Zone put the GPU through 3DMark 11 (a DirectX 11 graphics benchmark) and ComputeMark (a GPU compute shader benchmark that heavily loads system bus). The performance figures between the two were agonizingly insignificant. 3DMark 11 and ComputeMark are tell-tale tests of whether the GPU (and with it, its system interface) is at least getting loaded enough. You would much rather spend the money you saved to upgrade your current, perfectly-functional LGA1155 motherboard to an "ooh-Gen3" one, on a memory upgrade, before DRAM prices rebound.



One area, however, where Gen 3.0 could have a performance incentive, could be with future Ivy Bridge LGA1155 platforms, where to run 2-way CrossFire, the single x16 link from the CPU is split into two PCI Express 3.0 x8 links. Those numbers could be interesting.

View at TechPowerUp Main Site
 
Joined
Aug 29, 2011
Messages
83 (0.02/day)
Location
Somewhere I Belong
The current GFX can't use maximum bandwidth of PCIE 2.0, so how can they make a difference on PCIE 3.0?
 
Joined
Jan 11, 2005
Messages
1,491 (0.20/day)
Location
66 feet from the ground
System Name 2nd AMD puppy
Processor FX-8350 vishera
Motherboard Gigabyte GA-970A-UD3
Cooling Cooler Master Hyper TX2
Memory 16 Gb DDR3:8GB Kingston HyperX Beast + 8Gb G.Skill Sniper(by courtesy of tabascosauz &TPU)
Video Card(s) Sapphire RX 580 Nitro+;1450/2000 Mhz
Storage SSD :840 pro 128 Gb;Iridium pro 240Gb ; HDD 2xWD-1Tb
Display(s) Benq XL2730Z 144 Hz freesync
Case NZXT 820 PHANTOM
Audio Device(s) Audigy SE with Logitech Z-5500
Power Supply Riotoro Enigma G2 850W
Mouse Razer copperhead / Gamdias zeus (by courtesy of sneekypeet & TPU)
Keyboard MS Sidewinder x4
Software win10 64bit ltsc
Benchmark Scores irrelevant for me
The current GFX can't use maximum bandwidth of PCIE 2.0, so how can they make a difference on PCIE 3.0?

they can in your pocket....e-peen had sometimes a major buying decision :laugh:
 
Joined
Nov 11, 2008
Messages
231 (0.04/day)
Location
Atlanta, USA
Yeah this one was an e-peen festival from the manufacturer standpoint; they were lining up to compare peen's while we were like WTF, another same model board? What's the difference?
 
Joined
Apr 21, 2008
Messages
5,250 (0.86/day)
Location
IRAQ-Baghdad
System Name MASTER
Processor Core i7 3930k run at 4.4ghz
Motherboard Asus Rampage IV extreme
Cooling Corsair H100i
Memory 4x4G kingston hyperx beast 2400mhz
Video Card(s) 2X EVGA GTX680
Storage 2X Crusial M4 256g raid0, 1TbWD g, 2x500 WD B
Display(s) Samsung 27' 1080P LED 3D monitior 2ms
Case CoolerMaster Chosmos II
Audio Device(s) Creative sound blaster X-FI Titanum champion,Creative speakers 7.1 T7900
Power Supply Corsair 1200i, Logitch G500 Mouse, headset Corsair vengeance 1500
Software Win7 64bit Ultimate
Benchmark Scores 3d mark 2011: testing
I think nvidia will be work on that, other thing i see 7990 will use pci-e 3.0
 
Joined
May 19, 2007
Messages
4,520 (0.70/day)
Location
Perth AU
Processor Intel Core i9 10980XE @ 4.7Ghz 1.2v
Motherboard ASUS Rampage VI Extreme Omega
Cooling EK-Velocity D-RGB, EK-CoolStream PE 360, XSPC TX240 Ultrathin, EK X-RES 140 Revo D5 RGB PWM
Memory G.Skill Trident Z RGB F4-3000C14D 64GB
Video Card(s) Asus ROG Strix GeForce RTX 4090 OC WC
Storage M.2 990 Pro 1TB / 10TB WD RED Helium / 3x 860 2TB Evos
Display(s) Samsung Odyssey G7 28"
Case Corsair Obsidian 500D SE Modded
Power Supply Cooler Master V Series 1300W
Software Windows 11
There probably using a old bios 1005 which isn't released on the asus website has

update microcode, pcie gen 3.0 codes

Which are probably needed.
 

Over_Lord

News Editor
Joined
Oct 13, 2010
Messages
764 (0.15/day)
Location
Hyderabad
System Name BAH! - - tHE ECo FReAK
Processor Athlon II X4 620 @ 1.15V
Motherboard ASUS 785G EVO
Cooling Stock
Memory Corsair Titanium 4GB DDR3 1600MHz C9
Video Card(s) Sapphire HD5850 @ 1.049v
Storage Seagate 7200.12 500GB
Display(s) BenQ G2220HD
Case Cooler Master Elite 334
Audio Device(s) Onboard
Power Supply Corsair VX550W
Software Windows 7 Ultimate x64
yet again if HD7970 wouldn't have supported PCIe 3.0, it would have definitely gone into the negatives of many reviews.
 

R_1

Joined
Dec 1, 2006
Messages
448 (0.07/day)
Don't know if it is fair comparison, because SandyBridge CPU has only 16 PCIe lines for external GPU, where SB-E got 40 PCIe lines. So ASUS probably hardwired them as 1x16 + 3x8 in Z79. That configuration benefits old PCIe 2.0, because 1x16 graphics slot has always 16 PCIe lines connected to it, where SandyBridge mobo will implement for primary graphics only 8 PCIe wired lines + another 8, by switching IC, if another external GPU is nod conected. If that switching IC is Gen2, then it cann't operate in PCIe 3.0 CPU environment and no additional 8 PCIe can be added.
 

mum1989

New Member
Joined
Oct 27, 2010
Messages
9 (0.00/day)
Location
france
System Name Windows 7 x64 ultimate & Archlinux X64
Processor AMD Phenom II X6 1055T @3.5ghz
Motherboard Gigabyte MA770T-UD3P
Cooling OCZ vendetta 2
Memory G.Skill Sniper (Kit 2x4Go) DDR3 PC3-12800 - CL9
Video Card(s) AMD (XFX) 5870 1go
Storage SSD OCZ Agility 2 40go, Samsung F3 7200tr/min 1To & Seagate (7200.12) 500Go
Display(s) LG 2361v
Case Fractal Design Arc
Audio Device(s) on motherboard
Power Supply LEPA B750-MA
Joined
Nov 16, 2006
Messages
2,724 (0.41/day)
Location
Blighty
Processor R7 5800x3D
Motherboard MSI x570 Tomahawk
Cooling XSPC Raystorm Edge,EK QS P420M,EK D5pwm Revo Res
Memory 32gb Corsair Vengeance RT 3600 cl16
Video Card(s) Zotac 3070ti Amp Extreme
Storage Samsung 980pro 1tb x2
Display(s) MSI MPG321QRF QD
Case Corsair 7000D
Power Supply EVGA 1000 P2
Mouse G900
Keyboard Corsair k60 RGB PRO
Software Win 11
One area, however, where Gen 3.0 could have a performance incentive, could be with future Ivy Bridge LGA1155 platforms, where to run 2-way CrossFire, the single x16 link from the CPU is split into two PCI Express 3.0 x8 links

This is the only situation i was expecting any improvement in anyway
 
Joined
Apr 6, 2009
Messages
227 (0.04/day)
Location
Finland
Processor 5800X
Motherboard Strix B550
Memory 32GB 3600MHz
Video Card(s) EVGA GTX 1070 SC Black Edition
um.. anandtech says otherwise:
Simply enabling PCIe 3.0 on our EVGA X79 SLI motherboard (EVGA provided us with a BIOS that allowed us to toggle PCIe 3.0 mode on/off) resulted in a 9% increase in performance on the Radeon HD 7970. This tells us two things: 1) You can indeed get PCIe 3.0 working on SNB-E/X79, at least with a Radeon HD 7970, and 2) PCIe 3.0 will likely be useful for GPU compute applications, although not so much for gaming anytime soon.
 
Joined
Apr 7, 2011
Messages
1,380 (0.28/day)
System Name Desktop
Processor Intel Xeon E5-1680v2
Motherboard ASUS Sabertooth X79
Cooling Intel AIO
Memory 8x4GB DDR3 1866MHz
Video Card(s) EVGA GTX 970 SC
Storage Crucial MX500 1TB + 2x WD RE 4TB HDD
Display(s) HP ZR24w
Case Fractal Define XL Black
Audio Device(s) Schiit Modi Uber/Sony CDP-XA20ES/Pioneer CT-656>Sony TA-F630ESD>Sennheiser HD600
Power Supply Corsair HX850
Mouse Logitech G603
Keyboard Logitech G613
Software Windows 10 Pro x64
Joined
Dec 2, 2009
Messages
3,352 (0.61/day)
System Name Dark Stealth
Processor Ryzen 5 5600x
Motherboard Gigabyte B450M Gaming rev 1.0
Cooling Snowman, arctic p12 x2 fans
Memory 16x2 DDR4 Corsair Dominator Pro
Video Card(s) 3080 10gb
Storage 2TB NVME PCIE 4.0 Crucial P3 Plus, 1TB Crucial MX500 SSD, 4TB WD RED HDD
Display(s) HP Omen 34c (34" monitor 3440x1440 165Hz VA panel)
Case Zalman S2
Power Supply Corsair 750TX
Mouse Logitech pro superlight, mx mouse s3, Razer Basiliskx with battery
Keyboard Custom mechanical keyboard tm680
Software Windows 11
Benchmark Scores 70-80 fps 3440x1440 on cyberpunk 2077 max settings
I dont really think this is true
See the facts:
PCI-express 2 has at max 80GT/s
The card itself has 137GT/s
It can be an asus program failure too or bad programming
Look at pci-express and make a difference with 7970 in gpu-z
http://en.wikipedia.org/wiki/PCI_Express
 

von kain

New Member
Joined
Sep 13, 2006
Messages
780 (0.12/day)
Location
athens/greece
System Name intel-hate
Processor Amd phenom 2 955 @ 3800
Motherboard msi 790fx-gd70
Cooling coolermaster
Memory 4096 @1600 corsair
Video Card(s) sapphire 5770 @950-1350
Storage 1 seagate 80gb sata2 1 160gb seagate sata
Display(s) 20inch wide lg
Power Supply chieftech 750w
Software windows 7 x64
Benchmark Scores nah
wait for a crossfire bench.
 
Joined
May 20, 2004
Messages
10,487 (1.39/day)
I dont really think this is true
See the facts:
PCI-express 2 has at max 80GT/s
The card itself has 137GT/s
It can be an asus program failure too or bad programming

And all that data has to go over the bus? I don't think so.

It's no surprise, new standards never get utilized right away. They simply have to be there for companies to adopt and later on they will have added value. Same was true for PCI to AGP (banshee PCI or AGP, which is faster?), then to various AGP standards and then AGP vs PCIe, then PCIe 2.0 and now 3.0. All I can say is "doh".
 
Joined
Dec 2, 2009
Messages
3,352 (0.61/day)
System Name Dark Stealth
Processor Ryzen 5 5600x
Motherboard Gigabyte B450M Gaming rev 1.0
Cooling Snowman, arctic p12 x2 fans
Memory 16x2 DDR4 Corsair Dominator Pro
Video Card(s) 3080 10gb
Storage 2TB NVME PCIE 4.0 Crucial P3 Plus, 1TB Crucial MX500 SSD, 4TB WD RED HDD
Display(s) HP Omen 34c (34" monitor 3440x1440 165Hz VA panel)
Case Zalman S2
Power Supply Corsair 750TX
Mouse Logitech pro superlight, mx mouse s3, Razer Basiliskx with battery
Keyboard Custom mechanical keyboard tm680
Software Windows 11
Benchmark Scores 70-80 fps 3440x1440 on cyberpunk 2077 max settings
So you mean that the card is not giving its full potential?
Because of the bus?
 

sneekypeet

not-so supermod
Staff member
Joined
Apr 12, 2006
Messages
29,630 (4.34/day)
System Name EVA-01
Processor Intel i7 13700K
Motherboard Asus ROG Maximus Z690 HERO EVA Edition
Cooling ASUS ROG Ryujin III 360 with Noctua Industrial Fans
Memory PAtriot Viper Elite RGB 96GB @ 6000MHz.
Video Card(s) Asus ROG Strix GeForce RTX 3090 24GB OC EVA Edition
Storage Addlink S95 M.2 PCIe GEN 4x4 2TB
Display(s) Asus ROG SWIFT OLED PG42UQ
Case Thermaltake Core P3 TG
Audio Device(s) Realtek on board > Sony Receiver > Cerwin Vegas
Power Supply be quiet DARK POWER PRO 12 1500W
Mouse ROG STRIX Impact Electro Punk
Keyboard ROG STRIX Scope TKL Electro Punk
Software Windows 11
I bet MSI would argue these findings....there had to be some reason to slam Gigabyte as hard as they did when they called them out for not having it, like it was the end of PCI-e tech as we knew it without 3.0 on a board:roll:
 
  • Like
Reactions: w3b
Joined
Apr 10, 2010
Messages
1,864 (0.35/day)
Location
London
System Name Jaspe
Processor Ryzen 1500X
Motherboard Asus ROG Strix X370-F Gaming
Cooling Stock
Memory 16Gb Corsair 3000mhz
Video Card(s) EVGA GTS 450
Storage Crucial M500
Display(s) Philips 1080 24'
Case NZXT
Audio Device(s) Onboard
Power Supply Enermax 425W
Software Windows 10 Pro

R_1

Joined
Dec 1, 2006
Messages
448 (0.07/day)
People are reporting 24% difference in Mediashow Expresso between PCIe 2 and 3 mode on Z79, so here it is. :laugh:
 

red-die

New Member
Joined
Sep 13, 2011
Messages
4 (0.00/day)
Processor i7 2600K
Motherboard P67 Fat-boi
Cooling Custome Air
Memory 16GB Vengeance 1600MHz
Video Card(s) 2x 9600GT 512MB
Storage 6X HDD
Display(s) Dell 24" 2407WFP-HC
Power Supply Seasonic S12D 750W
Software Win 7 64bit
PCI-E a AGP?

dudes...guys... bro...

pci-e is not for GC only
so the development are not for GC exclusive

GC has been always have the best performance when the standard become common
not as a pioneer in pushing it

so the 1st pci-e 3.0 gc?
its like moving from a cramped apartment to a big mansion,
so much space now but it will get filled later on'
 
Joined
Dec 14, 2011
Messages
1,087 (0.23/day)
Location
South-Africa
Processor AMD Ryzen 9 5900X
Motherboard ASUS ROG STRIX B550-F GAMING (WI-FI)
Cooling Noctua NH-D15 G2
Memory 32GB G.Skill DDR4 3600Mhz CL18
Video Card(s) ASUS GTX 1650 TUF
Storage SAMSUNG 990 PRO 2TB
Display(s) Dell S3220DGF
Case Corsair iCUE 4000X
Audio Device(s) ASUS Xonar D2X
Power Supply Corsair AX760 Platinum
Mouse Razer DeathAdder V2 - Wireless
Keyboard Corsair K70 PRO - OPX Linear Switches
Software Microsoft Windows 11 - Enterprise (64-bit)
This will be very handy when you start running 4x GFX Cards in SLi / Crossfire.
 
Joined
Feb 7, 2006
Messages
739 (0.11/day)
Location
Austin, TX
System Name WAZAAM!
Processor AMD Ryzen 3900x
Motherboard ASRock Fatal1ty X370 Pro Gaming
Cooling Kraken x62
Memory G.Skill 16GB 3200 MHz
Video Card(s) EVGA GeForce GTX 1070 8GB SC
Storage Micron 9200 Max
Display(s) Samsung 49" 5120x1440 120hz
Case Corsair 600D
Audio Device(s) Onboard - Bose Companion 2 Speakers
Power Supply CORSAIR Professional Series HX850
Keyboard Corsair K95 RGB
Software Windows 10 Pro
Also, most users have "mainstream" systems (sandybridge). I'd imagine the difference between 2.0 and 3.0 has more of an impact when your 16 lanes are cut to 8 per card in dual-GPU setups.

And as a couple people already mentioned, makes a significant difference in compute.
 

INSTG8R

Vanguard Beta Tester
Joined
Nov 26, 2004
Messages
8,081 (1.10/day)
Location
Canuck in Norway
System Name Hellbox 5.1(same case new guts)
Processor Ryzen 7 5800X3D
Motherboard MSI X570S MAG Torpedo Max
Cooling TT Kandalf L.C.S.(Water/Air)EK Velocity CPU Block/Noctua EK Quantum DDC Pump/Res
Memory 2x16GB Gskill Trident Neo Z 3600 CL16
Video Card(s) Powercolor Hellhound 7900XTX
Storage 970 Evo Plus 500GB 2xSamsung 850 Evo 500GB RAID 0 1TB WD Blue Corsair MP600 Core 2TB
Display(s) Alienware QD-OLED 34” 3440x1440 144hz 10Bit VESA HDR 400
Case TT Kandalf L.C.S.
Audio Device(s) Soundblaster ZX/Logitech Z906 5.1
Power Supply Seasonic TX~’850 Platinum
Mouse G502 Hero
Keyboard G19s
VR HMD Oculus Quest 3
Software Win 11 Pro x64
The current GFX can't use maximum bandwidth of PCIE 2.0, so how can they make a difference on PCIE 3.0?

Pretty much my comment on it. Pure marketing nothing more...
 

cadaveca

My name is Dave
Joined
Apr 10, 2006
Messages
17,232 (2.52/day)
No CPU out there actually supports PCIe 3.0, so why is this discussion even taking place? I can set my SB-E CPU to PCIe 3.0, sure...but does it work? NO!!!

So, the tech is not enabled fully, and you got no performance increase. Well, blow me over, I cannot imagine why. :rolleyes:


Where can PCIe 3.0 be used, currently? INTER-GPU COMMUNICATION. Crossfire, with multiple cards. Higher bandwidth for inter-GPU communication is needed, period.


:shadedshu
 
Top